Symposium Organizers
Yan Wang, Worcester Polytechnic Institute
Chang-Jun Bae, Korea Institute of Materials Science
Juergen Janek, Justus-Liebig Univ-Giessen
Jun Wang, A123 Systems, LLC
ES06.01: Solid Electrolyte I
Session Chairs
Monday PM, November 27, 2017
Hynes, Level 2, Room 203
8:30 AM - *ES06.01.01
The ARPA-E Ionics Program—Separators to Enable the Cycling of Lithium Metal
Paul Albertus 1 , Susan Babinec 1 , Scott Litzelman 2
1 , Advanced Research Projects Agency-Energy (ARPA-E), Washington, District of Columbia, United States, 2 , Booz Allen Hamilton, Washington, District of Columbia, United States
Show AbstractARPA-E has funded five themed Programs and spent >$200 million on advancing energy storage technology since its inception. Unfortunately, the ultimate impacts of some of the technical advances made within ARPA-E efforts, as well as advances developed outside of ARPA-E, are hindered by constraints arising from separator cost and performance limitations. In response to this situation, ARPA-E launched the IONICS (Integration and Optimization of Novel Ion-Conducing Solids) program in 2016. The 16 teams in the program are focused on developing breakthrough separators that would be broadly enabling in different areas of electrochemical technology, and also amenable to cost effective manufacturing. The projects include both polymer and inorganic ion conducting separators that enable electrode chemistries that have been previously unsuccessful in practical devices. Project teams are focused on overcoming property tradeoffs to achieve a full set of required attributes, including conductivity, selectivity, stability, mechanical properties, manufacturability, cost, and others. This contrasts with a common approach of optimizing a single variable at the expense of others. The IONICS focus is on solids rather than liquids, due to inherent advantages in selectivity and mechanical properties offered by solids.
The IONICS program has three areas: (1) Li+ conductors that enable the cycling of the lithium metal electrode at 25°C and at conditions required for high-energy cells, (2) highly selective polymer separators for flow batteries, and (3) anion-conducting polymer separators for use in alkaline fuel cells and electrolyzers. This talk will focus on area (1), where the cycling of lithium metal at conditions relevant to high-energy cells still has not been shown, despite decades of research. Highlights of the talk will include: (1) presentation of a new figure depicting state-of-the-art cycling of lithium metal in both industry and research institutions, which reveals tradeoffs among the critical cycling metrics relevant to high-energy cells (i.e., cumulative capacity throughput, current density, and per-cycle areal capacity), (2) suggestion of test protocols that ensure proper interpretation of cycling data, and especially that electronic and ionic currents are distinguished, (3) the economics of film manufacturing, and the pathways to achieve the aggressive IONICS cost targets (<10 $/m2) required for widespread adoption for transportation or grid applications, and (4) the technical approaches being pursued in the program, with a focus on ceramics.
9:00 AM - ES06.01.02
Structural Analysis and Electrochemical Characterization of the Cation-Substituted Lithium-Ion Conductor Li1−xTi1−xMxOPO4 (M = Nb, Ta, Sb)
Patrick Hofmann 1 , Wolfgang Zeier 1 , Juergen Janek 1
1 Institute of Physical Chemistry, Justus Liebig University Giessen, Giessen Germany
Show AbstractLithium ion batteries (LIB) offer the highest energy density of all rechargeable battery systems and are used in portable electronic devices as well as in electric vehicles (EVs).[1] Among suitable candidates for anode materials in LIBs the transition metal titanium oxyphosphates (M0.5TiOPO4) have been proposed.[2,3] Changes in the crystal structure of the material caused by transition metal doping can be used to adjust its electrochemical properties like ionic conductivity or activation energy as also shown for NASICON-type solid electrolytes.[4]
As LiTiOPO4 has recently been proposed as an anode material for lithium ion batteries,[3] a more fundamental understanding of the structure-property relationships is necessary. In this work, different cation-doped Li1−xTi1−xMxOPO4 (M = Nb5+, Ta5+, Sb5+) compositions were characterized by means of changes in crystal structure and electrochemical behavior. We show the influence of aliovalent doping with differently sized transition metal ions on the materials crystal structure and thus the ionic conductivity and activation energy. Additionally, polyhedral volumes of (Ti/M)O6 octahedra and PO4 tetrahedra and distortion index of (Ti/M)O6 polyhedra reveal a phase transformation within the highly doped samples. Using the experimentally obtained structural information, density functional theory is employed to determine theoretical diffusion pathways of the lithium ions and corresponding activation barriers. This study provides a comprehensive structural analysis of cation-doped LiTiOPO4 and changes of electrochemical behavior confirmed by DFT.
[1] J. Janek, W. G. Zeier, Nat. Energy 2016, 1, 16141.
[2] P. Bleith, P. Novak, C. Villevieille, J. Electrochem. Soc. 2013, 160, A1534-A1538.
[3] Y. Fu, H. Ming, S. Zhao, J. Guo, M. Chen, Q. Zhou, J. Zheng, Electrochim. Acta 2015, 185, 211.
[4] P. Zhang, H. Wang, Q. Si, M. Matsui, Y. Takeda, O. Yamamoto, N. Imanishi, Solid State Ion. 2015, 272, 101.
9:15 AM - ES06.01.03
Ionic Conductivity of Dense Li-Ion Solid Electrolytes
Jeff Wolfenstine 1 , Jan Allen 1 , Jeff Sakamoto 2
1 , Army Research Laboratory, Adelphi, Maryland, United States, 2 , University of Michigan, Ann Arbor, Michigan, United States
Show AbstractSolid Li-ion conducting electrolytes are receiving considerable attention recently because, their use can lead to higher energy (Li anode and/or high voltage cathodes) and safer (non-flammable electrolyte) batteries compared to the current Li-ion batteries based on organic electrolytes. One of the major requirements in the choice of a Li-ion conducting solid electrolyte is high total Li-ion conducting. The total Li-ion conductivity of a solid electrolyte is a function of: 1] crystal structure (e.g., garnet), 2] chemistry (e.g., Li content) and 3] microstructure (e.g., grain size). It is the purpose of this presentation to discuss and compare the total Li-ion conductivity of solid electrolytes for three different crystal structures (NaSICON, Garnet and Perovskite) consolidated to near theoretical density using hot-pressing.
9:30 AM - ES06.01.04
Correlating Transport and Structural Properties in Li1+xAlxGe2−x(PO4)3 Prepared from Aqueous Solutions
Manuel Weiß 1 , Wolfgang Zeier 1 , Juergen Janek 1
1 Institute of Physical Chemistry, Justus Liebig University, Giessen Germany
Show AbstractThe solid lithium ion conductor Li1+xAlxGe2−x(PO4)3 (LAGP) belongs to the NASICON family, crystallizes in the R-3c space group, and is generally considered as a solid electrolyte for solid-state batteries[1]. Mostly, it is prepared in a complicated and costly high-temperature process from melt at above 1300 °C[2]. Another method is the Pechini-type sol-gel process using expensive germanium(IV) ethoxide[3]. We show a simple synthesis route from aqueous solution employing significantly less expensive GeO2 and a sintering temperature of only 800 °C.
Germanium can be substituted by aluminum in order to increase the Li+ concentration[4]. We have obtained experimental data that show the influence of Al content on the ionic conductivity (determined by impedance spectroscopy). Using synchrotron diffraction data the occupancy of Al on the Ge site was obtained. Additionally, we have used neutron diffraction to determine the Li positions and the distribution of Li on the 6b and 18e sites.
We show that the actual Li+ concentration in the samples is proportional to the nominal value, whereas a solubility limit is present at higher contents. Further added aluminum and lithium promote the formation of side phases. The lattice parameters and cell volume follow the same trend.
Ionic conductivity behaves accordingly and increases with growing Li+ concentration as expected. In order to understand the bulk activation energy, however, deep insights into the structural parameters are necessary. The behavior of the activation energy can only be explained as an interplay of polyhedral volumes, hopping distances and charge carrier concentration. In this work, we will present the influence of the local polyhedral structure on the ionic transport in this important class of materials.
[1] J. Janek, W. G. Zeier, Nat. Energy 2016, 1, 16141.
[2] J. S. Thokchom, N. Gupta, B. Kumar, J. Electrochem. Soc. 2008, 155, A915.
[3] B. E. Francisco, C. R. Stoldt, J.-C. M’Peko, Chem. Mater. 2014, 26, 4741.
[4] V. Epp, Q. Ma, E.-M. Hammer, F. Tietz, M. Wilkening, Phys. Chem. Chem. Phys. 2015, 17, 32115.
9:45 AM - ES06.01.05
Design of Novel Alkali Superionic Conductors via Efficiently Tiered Ab Initio Molecular Dynamics Simulations
Zhuoying Zhu 1 , Iek-Heng Chu 1 , Shyue Ping Ong 1
1 , University of California, San Diego, La Jolla, California, United States
Show AbstractSuperionic conductor solid electrolytes are the critical component in all-solid-state rechargeable alkali-ion batteries, a potentially safer, more energy dense architecture for energy storage. Despite recent progresses, the total number of known alkali superionic conductors remain relatively small, and most of them have significant compromises. In this talk, we will present two promising novel alkali superionic conductors, Li3Y(PS4)2 and Li5PS4Cl21, predicted from first principles calculations. We will demonstrate that a tiered first principles screening approach, which combines computationally inexpensive topological analysis with relatively short ab initio molecular dynamics simulations, can be used to rapidly exclude candidates that are unlikely to meet the demanding ionic conductivity requirements for superionic conductors. Li3Y(PS4)2, in particular, exhibits a predicted room-temperature Li+ conductivity of 2.16 mS/cm, which can be increased multifold to 7.14 and 5.25 mS/cm via aliovalent doping with Ca2+ and Zr4+, respectively. More critically, we show that the phase and electrochemical stability of Li3Y(PS4)2 is expected to be better than current state-of-the-art lithium superionic conductors such as Li10GeP2S122, Li9.54Si1.74P1.44S 11.7Cl0.33 and Li7P3S11.
References:
1. Zhu, Z., Chu, I.-H. & Ong, S. P. Li3Y(PS4)2 and Li5PS4Cl2, New Lithium Superionic Conductors Predicted from Silver Thiophosphates using Efficiently Tiered Ab Initio Molecular Dynamics Simulations. Chem. Mater. 29, 2474-2484 (2017).
2. Kamaya, N. et al. A lithium superionic conductor. Nat. Mater. 10, 682–686 (2011).
3. Kato, Y. et al. High-power all-solid-state batteries using sulfide superionic conductors. Nat. Energy 1, 16030 (2016).
10:30 AM - *ES06.01.06
Garnet Nanostructures toward Advanced Li Metal Batteries
Liangbing Hu 1
1 , University of Maryland, College Park, Maryland, United States
Show AbstractSolid state electrolytes are known for non-flammability, dendrite blocking, and stability over large potential windows. Garnet-based solid-state electrolytes have attracted much attention for their high ionic conductivities and stability with lithium metal anodes. However, high interface resistance with lithium anodes hinders their application to lithium metal batteries. I will discuss our recent progress on Li metal batteries using multilayer Garnet nanostructures, including the following aspects:
1. Garnet nanofibers and hybrid flexible solid state electrolytes;
2. Nanoscale engineering to solve Li metal-Garnet interfaces, including PECVD Si, ALD oxides and ultrathin metals;
3. In-situ neutron depth profiling technique in understanding Li-garnet and CNT-garnet interfaces;
4. Cathode-garnet interface engineering;
5. Li metal batteries using garnet electrolytes.
References:
Fu, K.; Gong, Y.; Li, Y.; Xu, S.; Wen, Y.; Zhang, L.; Wang, C.; Pastel, G.; Dai, J.; Liu, B.; Xie, H., Yao, Y.; Wachsman, E.; Hu, L. Three-Dimensional Bilayer Garnet Solid Electrolyte Based High Energy Density Lithium Metal-Sulfur Batteries. Energy & Environmental Science, 2017, accepted.
Fu, K.; Gong, Y.; Liu, B.; Zhu, Y.; Xu, S.; Yao, Y.; Luo, W.; Wang, C.; Lacey, S.; Dai, J.; Chen, Y.; Mo, Y.; Wachsman, E.; Hu, L. Towards Garnet Electrolyte-based Li metal batteries: An Ultrathin, Highly Effective Artificial Solid-State Electrolyte/Metallic Li Interface, Science Advance, 2016, accepted.
Han, X.; Gong, Y.; Fu, K.K.; He, X.; Hitz, G.T.; Dai, J.; Pearse, A.; Liu, B.; Wang, H.; Rubloff, G.; Mo, Y., Thangadurai, V.; Wachsman.; Hu, L. Negating Interfacial Impedance in Garnet-Based Solid-State Li Metal Batteries, Nature Materials, 2016, online.
Luo, W.; Gong, Y.; Zhu, Y.; Fu, K. K.; Dai, J.; Lacey, S. D.; Wachsman, E. D.; Hu, L. Transition from Superlithiophobicity to Superlithiophilicity of Garnet Solid-State Electrolyte, JACS, 2016, 138, 12258.
Fu, K.; Gong, Y.; Dai, J.; Gong, A.; Han, X.; Yao, Y.; Wang, Y.; Wang, C.; Chen, Y.; Yan, C.; Li, Y.; Wachsman, E.; Hu, L. Flexible, Solid-State Lithium Ion-conducting Membrane with 3D Garnet Nanofiber Networks, PNAS, 2016, 113, 26,7094.
11:00 AM - ES06.01.07
Sol-Gel-Processed Amorphous LiLaTiO3 Thin Film as Solid Electrolyte
Yubin Zhang 1 , Zhangfeng Zheng 1 , Yan Wang 1
1 Department of Materials Science and Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts, United States
Show AbstractAmorphous lithium lanthanum titanium oxide (LLTO) is a promising inorganic solid electrolyte for all-solid state lithium ion batteries. Preparation of amorphous LLTO thin films by sol-gel process with a partially hydrolyzed sol has been reported. The ionic conductivities of amorphous LLTO thin films were 4.5*10−6, 6.9*10−6, 1.3*10−5, and 3.8*10−5 S/cm at 30°C, 50°C, 70°C, and 90°C, respectively. However, the relationship between microstructure and ionic conductivity hasn’t been unraveled. In this study, we prepared amorphous LLTO thin film with two different sol-gel methods, all-alkoxide and acetate–alkoxide routes. XRD and TEM were applied to demonstrate two thin films prepared from these two routes are amorphous. SEM results proved that both thin films are dense and crack-free. In addition, different surface morphologies are observed and it is measured the ionic conductivity of the thin film prepared from the all-alkoxide route (1.78*10-5 S/cm at 30°C) is almost two orders higher than that from the acetate–alkoxide route (1.86*10-7 S/cm at 30°C), which comes from different sol chemistries. The all-alkoxide route follows one-step decomposition mechanism, whereas the acetate-alkoxide route undergoes two-step one via carbonate formation.
11:15 AM - ES06.01.08
Li Doping Behavior in KI-KBH4 Solid Solvent and Its Li+ Ion Conduction Properties
Reona Miyazaki 1 , Yasuto Noda 2 , Hidetoshi Miyazaki 1 , Kazuo Soda 3 , Takehiko Hihara 1
1 , Nagoya Institute of Technology, Nagoya Japan, 2 , Kyoto University, Kyoto Japan, 3 , Nagoya University, Nagoya Japan
Show AbstractSolid electrolytes, where Li+ can migrate fast in their crystal lattice, are the key materials for realization of high performance all-solid-state lithium batteries. From the early stage of the research, most of the works have focused on compounds containing Li+ in themselves. Some of the Li compounds show extremely high Li+ conductivity comparable to that in liquid electrolytes and are so-called Li+ superionic conductors [1].
Li+ ion conductors can also be synthesized by the doping of Li salts into “Li-free” solid solvents. It has been proven that both KI and NaI can be changed to Li+ ion conductors via doping small amount of LiBH4 [2][3]. From the past report, the presence of BH4- is believed to be effective for the enhancement of the thermal stability of Li+ ions in NaI [4]. In this work, in order to clarify the effect of BH4- anion on the Li doping behavior and Li+ conduction properties in KI, several composition of KI-KBH4 solid solvents are fabricated and then LiI is doped as a Li salt.
All the experiments were conducted in an Ar atmosphere. The reagents were mixed by hand in an alumina mortar at a given molar ratio. Using an air tight chrome steel pot (45 ml) and 10 pieces of balls (10 mm in diameter), they were milled at 400 rpm for 5 hours. For the analysis of the crystal and local structure of the samples, XRD measurement with Cu Kα radiation and 7Li NMR were performed, respectively. An electrical conductivity was measured by AC impedance methods between 303 K and 423 K. The powder sample was pelletized at approximately 150 MPa and Li and/or Mo foils were fixed at the both sides of the pellets.
From the results of XRD measurement for KI-LiI system, the peak positions are not changed from those of KI and unreacted LiI is segregated, which means that KI and LiI does not form a solid solution. However, according to the previous report, Li+ can be doped into KI lattice in the form of LiBH4 doping [2]. When I- ions in KI is partially substituted by BH4-, it is confirmed that approximately 30 mol% of LiI can be dissolved in KI-KBH4 and unreacted LiI is not detected as XRD peaks. Therefore, it can be concluded that Li+ ions in KI are drastically stabilized by the presence of BH4- anions. Furthermore, the crystal lattice of the solid solvent is expanded by LiI doping, whose results cannot be explained by the substitution of native K+ sites by Li+ because of the smaller ionic size of Li+ than K+. Therefore, it can be expected that doped Li+ ions maybe occupy the interstitial sites of KI lattice. The detailed Li+ sites in the solid solvent and the Li+ ion conduction properties in KI-KBH4-LiI system will be presented at the meeting.
References
[1] P. Knauth, Solid State Ionics 180 (2009) 911.
[2] R. Miyazaki et al., APL Materials 2 (2014) 056109.
[3] R. Miyazaki et al., J. Solid State Electrochem. 20 (2016) 2759.
[4] R. Miyazaki et al., MRS Advances, 2(7) (2017) 389.
11:30 AM - ES06.01.09
Universal Strategy to Design Super-Ionic Conductors through First Principles Computation
Xingfeng He 1 , Yizhou Zhu 1 , Yifei Mo 1 2
1 Department of Materials Science and Engineering, University of Maryland, College Park, Maryland, United States, 2 Energy Research Center, University of Maryland, College Park, Maryland, United States
Show AbstractLithium super-ionic conductor materials are the key component in enabling all-solid-state Li-ion batteries. However, it has not yet been understood why only a few materials as super-ionic conductors can achieve exceptionally higher ionic conductivity than typical solids and how one can design fast ion conductors following simple principles. Using ab initio modeling, we show that fast diffusion in super-ionic conductors happens through unique concerted migration mechanism of multiple ions with low energy barrier in contrast to isolated ion hopping in typical solids. We elucidate that low energy barriers of the concerted ionic diffusion are a result of unique mobile ion configurations and strong mobile ion interactions in super-ionic conductor materials, such as Li10GeP2S12, lithium garnet, NASICON, etc. Our theory provides a conceptually simple framework for guiding the design of super-ionic conductor materials. Using first principles computation, we demonstrate this strategy by designing a number of novel fast ion conducting materials, which have comparable high Li+ ionic conductivity to the known Li super-ionic conductor materials. In summary, our proposed theory and identified mechanism are universally for fast diffusion in a broad range of ionic conducting materials, and provide a general framework and a universal strategy to design solid materials with fast ionic diffusion. This study has recently been published in Nature Communications [1].
[1] Xingfeng He, Yizhou Zhu, Yifei Mo, “Origin of fast ion diffusion in super-ionic conductors”, Nat. Commun. 8, 15893 (2017).
11:45 AM - ES06.01.10
Modification of Voltage Stability in Sulfide Solid Electrolyte
Xin Li 1
1 , Harvard University, Cambridge, Massachusetts, United States
Show AbstractCeramic sulfide solid electrolyte has reached high lithium conductivity, while the voltage stability was reported as an issue in many previous literatures. We show in this talk several ways to improve the voltage stability of sulfide solid electrolyte materials by microstructure modification of the synthesized electrolyte materials. The improved battery performance and voltage stability are shown by electrochemical test. A combination of first principle simulation and transmission electron microscopy imaging techniques are used to understand the principle behind the phenomenon.
LGPS or LSPS has been reported with high lithium ion conductivity comparable or even higher than that of the commercial liquid electrolyte. However, the limited voltage stability of these sulfides was previously considered as a barrier for its application, as when cycled beyond its voltage stability window the sulfides decompose. We show that through microstructure modification on the nanoscale or atomic level, the voltage stability window can be opened up to give largely improved cycling performance. We show through TEM that the structure decomposition is largely suppressed in the modified sulfide electrolyte materials. We also from DFT simulation understand the principle behind this promising result and give our guidelines for the design of advanced sulfide electrolytes.
ES06.02: Solid Electrolyte II
Session Chairs
Monday PM, November 27, 2017
Hynes, Level 2, Room 203
1:30 PM - *ES06.02.01
Native Defects of Li10GeP2S12 and Its Effect on Lithium Diffusion
Kisuk Kang 1 , Kyungbae Oh 1
1 , Seoul National University, Seoul Korea (the Republic of)
Show AbstractDefects affect many key properties of materials and often play a crucial role. The Li diffusion in Li ion conductors is also significantly affected by defects. Particularly in all-solid-state Li ion battery system, facile Li diffusions in the structure are considered as important requirements for high power and rate capability. As a representative solid electrolyte material, Li10GeP2S12 structure was first reported with Li ionic conductivity of 12 mS/cm at room temperature in 2011. Since the Li10GeP2S12 was first reported as a one-dimensional conductor, the adverse effect of defects on the Li diffusion has been undoubtedly believed.
Herein, we report a first-principles study on the defect profile of Li10GeP2S12 for the first time. In addition, an effect of native defects on the Li diffusion behavior of Li10GeP2S12 is investigated based on the acquired defect profile. To consider the effect of experimental conditions on the defect formation energies, various chemical potential limits were applied in the calculations. It is found that VLi-, Lii+, Pa, Pc and PGe+ exist as major defects in Li10GeP2S12 regardless of the chemical environment, whereas the concentration of other defects including path-blocking defects were dependent on the experimental conditions. Ab-initio molecular dynamic (AIMD) simulations demonstrated that the defects generally facilitate the Li diffusion in Li10GeP2S12 unlike the conventional belief. We also suggest the structural reasons for the effect of defects by analyzing site occupancy and hopping rate. Meanwhile, we could find out key factors for fast Li diffusion in Li10GeP2S12 structure. This work is believed to provide a comprehensive perspective on the defective nature of Li10GeP2S12.
2:00 PM - ES06.02.02
Mineral Derived Lithium Solid Electrolyte
Bo Wang 1
1 , Imerys, San Jose, California, United States
Show AbstractLithium solid electrolyte with NASICON structure in the form of Li1+2xAlxTi2-xSixP3-xO12 solid solution has been prepared by high temperature solid state reaction using low cost kaolin as the starting material. The crystal structure of the solid solution was investigated by powder X-ray diffraction. The ac impedance measurements indicate that ionic conductivity increased by more than one order of magnitude when small amount of Al3+ and Si4+ ions were incorporated into the LiTi2(PO4)3 crystal structure. The significant improvement on ionic conductivity can be attributed to the increased interstitial Li+ ions in the crystal structure.
2:15 PM - ES06.02.03
Study of Atomic Layer Deposition Coating on Lithium Solid Electrolytes
Kia Chai Phuah 1 , Stefan Adams 1
1 , National University of Singapore, Singapore Singapore
Show AbstractLithium-based electrochemical energy storage has been an area of interest due to the demand for high energy-density devices. Such high energy-density devices are key enablers of green renewable technologies, portable applications as well as the proliferation of electric vehicles. Current commercial usage has lithium-ion batteries as the energy storage of choice due to its high energy density compared to alternatives such as nickel-metal hydride or lead-acid chemistries. Lithium-ion batteries however have also come under the spotlight for safety concerns, with recent occurences of unexpected short-circuits causing fires and hence posing a prominent danger given its ubiquity.
One direction of safety improvement for lithium-ion batteries is the replacement of the volatile liquid electrolyte with solid electrolytes instead. Lithium solid electrolytes are a class of solid materials that promise safety improvements compared to liquid electrolytes by eliminating leakage and evaporation risk, inhibition of lithium metal anode dendrite growth, as well as forming a physical barrier against internal short-circuit of the anode and cathode.
Many different types of solid electrolytes are currently under study, of which some examples are the argyrodites and lithium germanium phosphorus sulfides, which are sulfide-based, as well as the NASICON-type lithium aluminium germanium/titanium phosphates and garnets, which are oxide based. However, each type of solid electrolyte has its own specific challenges which prevent them from being drop-in replacements for the liquid electrolytes used today. Interfacial chemistries and other considerations are now key to building composite electrolytes that aim to overcome the various challenges facing solid electrolytes today.
Atomic layer deposition is a technique that is able to synthesize thin conformal coatings on solid substrates. This technique is very promising to enable thin layer coatings on solid electrolytes to provide enhanced functionality and to overcome their weaknesses. One example would be the protection of sulfide-based electrolytes with water-stable oxide coatings to improve its resistance to water.
In our research work, we study the interfacial changes to solid electrolytes by the use of atomic layer deposited coatings. We observe the structural changes using characterization methods such as electron microscopy, X-ray spectroscopy, and X-ray diffraction. Electrochemical stability is also observed using techniques such as cyclic voltammetry and impedance spectroscopy, to verify the feasibility of using these modified electrolytes in battery devices.
2:30 PM - ES06.02.04
Prussian Blue Analogue Structures for Grid Scale Electrodes Using High Throughput Density Functional Theory
Lea Boudinet 1 2 , Shyam Dwaraknath 2 , Kristin Persson 2 3
1 , École Normale Supérieure, Paris France, 2 , Lawrence Berkeley National Laboratory, Berkeley, California, United States, 3 Material Science, University of California, Berkeley, California, United States
Show AbstractRising awareness for climate change along with depletion of natural resources call for a major rebuild of our energy infrastructure. New technologies are needed to store, level-out, and redistribute power from renewable sources. Battery technologies have had primary application in smaller scale systems, but could serve as a effective storage if the right materials can be discovered. Prussian Blue Analogues (PBA) have shown promise in this area as potential solid electrolytes and electrodes by exhibiting good cyclability, low cost, and moderate capacity. However, a single PBA that exhibits all of these characteristics has yet to be found. High throughput density functional theory was used to investigate the PBA structure for electrode applications as a function of the transition metal and intercalation chemistry. Voltage curves, maximum capacity, volumetric changes during cycling, localization of redox activity, hydration necessary of global stability, and potential peak power were all characterized from these calculations. These parameters were then aggregated into rankings on estimated cyclability and performance that were finally weighted and combined to identify the 10 most promising systems for future investigation of PBA-based solid-state batteries.
2:45 PM - ES06.02.05
Electrochemical Redox Behavior of Li2S-P2S5 Lithium-Ion Conducting Solid Electrolytes
Tushar Swamy 1 , Xinwei Chen 1 , Yet-Ming Chiang 1
1 , Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
Show AbstractLithium-ion conducting solid electrolytes are a promising alternative to conventional liquid electrolytes for making fire resistant and thus safer Li-ion batteries. Recent improvements in the conductivity of sulfide-based (Li2S-P2S5) solid-state electrolytes (SSE) have prompted further investigation into their material properties and interfacial characteristics. Particularly, β-lithium thiophosphate (β-Li3PS4, LPS), owing to its high conductivity (~0.2 mS/cm), scalable synthesis route, and favorable bulk mechanical properties, is a potential electrolyte candidate for solid-state Li-ion batteries [1]. Existing issues, however, surround the LPS/electrode interface due to the limited electrochemical stability window of the SSE (1.7-2.31 V, theoretical [2]), posing high impedance at the high-voltage cathode interface [3]. In order to address the interfacial impedance issue, it is important to characterize its redox behavior outside its stable voltage window.
Here we have developed a novel technique based on cyclic voltammetry, which treats the LPS SSE, a model sulfide-based SSE, as an active material electrode and uses internal redox-capable standards to show that even in the absence of active material, LPS undergoes decomposition at the carbon interface producing a redox active interphase comprising of phosphorus and sulfur species. We find that as the cell voltage is cyclically swept outside the electrochemical stability voltage window of LPS SSE, these species undergo redox and the result is a constantly changing interfacial composition. This is unlike in case of liquid electrolytes which decompose into electrochemically irreversible species once reduced or oxidized. Ex-situ XPS surface analysis of the LPS/C interface revealed the formation of elemental sulfur and P2S5 upon oxidation of LPS SSE to 5 V vs. Li/Li+, confirming DFT-based theoretical predictions. In full cells operating under normal conditions, the electrochemically reversibility of the LPS/C interphase impacts graphite anodes and sulfur cathodes, but not high voltage oxide cathodes because LPS irreversibly oxidizes in the 2.31 – 5 V range. However, our data suggests that the formation of electrically resistive P2S5 passivating layer is responsible for the low rate capability of high voltage cathode interfaces.
Determining the properties of redox capable solid electrolyte/ high voltage cathode active material interface and developing methods to mitigate the formation of high impedance species is an essential next step for sulfide-based solid electrolyte research.
Acknowledgments
We gratefully acknowledge support from the US Department of Energy’s Office of Basic Energy Science for the Chemo-mechanics of Far-From-Equilibrium Interfaces (COFFEI) small group, through award number DE-SC0002633.
References
1. Z. Liu et al., J. Am. Chem. Soc., 135, 975–978 (2013)
2. Y. Zhu, et al., J. Mater. Chem. A, 4, 3253–3266 (2016)
3. N. Ohta et al., Electrochem. commun., 9, 1486–1490 (2007)
3:30 PM - *ES06.02.06
Insights into LISICON and NASICON Solid Electrolytes—Local Structures and Conduction Mechanisms
Saiful Islam 1
1 , University of Bath, Bath United Kingdom
Show AbstractMajor advances in solid-state lithium and sodium batteries require the discovery and characterization of new solid electrolyte materials. It is clear that a complete understanding of such materials requires fundamental knowledge of their underlying structural, transport and interface properties on the atomic- and nano-scales. This talk will highlight recent studies [1] on local structures and ion conduction mechanisms of important solid electrolyte systems: LISICON-type Li4SiO4-Li3PO4 and NASICON-type Na3Zr2Si2PO12. A combination of advanced modelling, diffraction, impedance and NMR techniques has helped us gain new insights into these complex materials, which are valuable in developing strategies to optimize their electrolyte properties.
[1] Y. Deng et al., J. Amer. Chem. Soc., 137, 9136 (2015); Y. Deng et al., ACS Appl. Mater. Interfaces, 9, 7050 (2017).
4:00 PM - ES06.02.07
Mesoscale Modeling Study of Microstructural Impacts on the Effective Ionic Diffusivity of Solid Electrolytes for Li Batteries
Tae Wook Heo 1 , Nicole Adelstein 2 , Brandon Wood 1
1 Materials Science Division, Lawrence Livermore National Laboratory, Livermore, California, United States, 2 Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California, United States
Show AbstractInorganic crystalline electrolytes represent promising solutions for building all solid-state batteries owing to their comparable ionic conductivities, electrochemical, mechanical, and thermal stabilities. The kinetics of ion transport in solid electrolytes is known to be highly sensitive to the topological characteristics of ion conduction pathways. The conduction mechanisms usually involve concurrent ionic diffusion along various mesoscopic features of an internal microstructure such as bulk grain, structural variant domain, and associated boundaries as well as their network, which largely depend upon their synthetic processing routes. Due to the complexity of these structural features of the solid electrolytes during operation, it is significantly challenging to characterize the microstructure-ionic diffusion property relationship. For better mechanistic understanding of relevant conduction mechanisms, it is necessary to thoroughly explore the impacts of individual microstructural factors on the overall kinetic properties and performances. In this presentation, we will present our development of an efficient and robust mesoscopic computational method for extracting the effective diffusivity of the solid electrolyte containing arbitrarily distributed microstructural inhomogeneities such as differently oriented multiple grains, several structural variants of phase domains, and grain/domain boundaries. Employing several types of three-dimensional digital microstructures generated by phase-field simulations as well as the fundamental diffusivity tensors of reference phases and boundaries derived from atomistic calculations as inputs, the method enable us to efficiently compute the effective diffusivity tensor of the entire system. We will then discuss the applications of this multiscale method to investigating the relationship between relevant individual microstructural features and effective diffusivity of highly conductive solid electrolytes (e.g., garnet Li7La3Zr2O12 (LLZO) and perovskite Li3xLa2/3-2xTiO3 (LLTO)) for Li batteries. In particular, our discussion will focus on the impacts of topological features of grains, internal mesoscopic structures of high- and low-temperature phase variant domains, and grain/phase domain boundary networks on the overall Li ion diffusion properties.
This work of was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
4:15 PM - ES06.02.08
Superionic Diffusion through Frustrated Energy Landscape
Davide Di Stefano 1 , Anna Miglio 1 , Koen Robeyns 1 , Yaroslav Filinchuk 1 , Marine Lechartier 2 , Anatoliy Senyshyn 3 , Hiroyuki Ishida 4 , Stefan Spannenberger 5 , Bernhard Roling 5 , Yuki Katoh 2 , Geoffroy Hautier 1
1 , Université Catholique de Louvain, Louvain-la-Neuve Belgium, 2 , Toyota Motor Europe NV/SA, Zaventem Belgium, 3 , Technische Universität München, Munich Germany, 4 , Toray Research Center, Inc., Otsu Japan, 5 , Philipps-Universität Marburg, Marburg Germany
Show AbstractSolid-state materials with extremely high ionic diffusion are necessary to many technologies including all-solid-state Li-ion batteries. Despite the strong efforts made towards the search for crystal structures leading high lithium diffusion, very limited number of compounds showing superionic diffusion are known and clear materials design principles are greatly sought for.
In this work, we present a new material exhibiting the largest Li-ion diffusion coefficient ever measured in a solid. We show extensive characterisation (neutron, X-ray diffraction, impedance and NMR) as well as theoretical studies. We rationalise the exceptional performances of this new superionic conductor through the concept of frustrated energy landscape. The absence of regular and undistorted lithium site to occupy leads to low energy barrier for diffusion as well as an exceptional pre-factor. Our work not only shines light on a new family of superionic conductors but offers a new design principle for discovering new ones.
4:30 PM - ES06.02.09
Computational Design and Prediction of Solid-State Na Ionic Conductors
Yan Wang 1 2 , William Richards 2 , Shou-Hang Bo 4 , Lincoln Miara 1 , Gerbrand Ceder 4 3
1 Advanced Materials Lab, Samsung Research America, Burlington, Massachusetts, United States, 2 Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States, 4 , Lawrence Berkeley National Laboratory, Berkeley, California, United States, 3 , University of California, Berkeley, Berkeley, California, United States
Show AbstractInorganic solid-state ionic conductors with high ionic conductivity are of great interest for their application in safe and high-energy-density solid-state batteries. Our previous study reveals that the crystal structure of several experimentally discovered ionic conductors (e.g., Li10GeP2S12 and Li7P3S11) contains a body-centered-cubic (bcc) arrangement of sulfur anions, and that such a bcc anion framework facilitates high ionic conductivity [1]. In this work, we apply well-developed first-principles computational techniques to search for new Na ionic conducting materials based on the existing bcc-type superionic conductors. Ab-initio molecular dynamics simulations predict extraordinarily high ionic conductivities of over 10 mS cm-1 at R.T. in several novel Na ionic conductors [2], exceeding the performance of currently known Na-ion solid-state conductors. Moreover, we investigate the thermodynamic stability of these predicted ionic conductors through a detailed analysis of the computational phase diagrams including finite temperature effects by phonon free energy calculations.
[1] Yan Wang et al., “Design principles for solid-state lithium superionic conductors,” Nat. Mater., 14, 1026-1031, (2015).
[2] Yan Wang et al., “Computational Prediction and Evaluation of Solid-State Sodium Superionic Conductors”, Chem. Mater., 29, 7475-7482, (2017)
4:45 PM - ES06.02.10
All-Solid-State Lithium-Sulfur Batteries Based on Newly Designed Li7P2.9Mn0.1S10.7I0.3 Superionic Conductor
Ruochen Xu 1 , Xinhui Xia 1 , Shuhan Li 1 , Shengzhao Zhang 1 , Xiuli Wang 1 , Jiangping Tu 1
1 Materials Science and Engineering, Zhejiang University, Hangzhou China
Show AbstractLithium ion batteries (LIBs) are becoming the “king” in the field of electrochemical energy storage and playing important roles in the electric vehicles and modern electronics. However, there is a haze among the prosperity of LIBs business. Owing to repeated explosion/fire accidents of electric cars and cell phones, people are reflecting and turning their attention to the safety issue of LIBs. All the findings are pointing to the fact that the liquid organic electrolyte is one of the culprits. So great efforts are dedicated to developing alternative high-performance electrolyte. In this context, solid electrolyte have come to the fore and attracted considerable attention. All-solid-state lithium ion batteries (ASSLIBs) are one of most promising candidates for next-generation LIBs due to the safe nonflammable inorganic solid electrolytes. However, despite great progress, most of the solid electrolytes have not reached the ionic conductivity requirement o for ASSLIBs. It is found that the ionic conductivity of sulfide electrolytes can be improved by substitution. Meanwhile, appropriate doping can reduce interfacial resistance between electrodes and solid electrolytes, leading to better high-rate performance. Furthermore, the doping strategy can also improve the chemical stability of solid electrolyte and expand the working voltage windows.
We have developed a solid electrolyte of Li7P2.9Mn0.1S10.7I0.3 synthesized by high-energy ball milling method. Interestingly, the as-prepared Li7P2.9Mn0.1S10.7I0.3 solid electrolyte shows high an ionic conductivity (5.6 mS cm−1 at room temperature) and high electrochemical stability (>5 V vs. Li/Li+). The sulfur composite cathode is prepared by two-step high-energy ball milling using sulfur as the active material, carbon black as the electronic conductive material and Li7P2.9Mn0.1S10.7I0.3 as the ionic conductive material. All-solid-state LSBs are fabricated and the electrochemical performance is thoroughly investigated. In view of these interesting characteristics, the sulfur composite cathode shows a large capacity of 796 mAh g−1 at 0.05 C, and much better cycling stability than the counterpart with organic liquid electrolyte. Our studies can provide valuable references for synthesis of Li superionic conductor for all-solid-state batteries.
ES06.03: Poster Session: Solid Electrolyte and Solid State Batteries
Session Chairs
Tuesday AM, November 28, 2017
Hynes, Level 1, Hall B
8:00 PM - ES06.03.01
Preparation and Evaluation of All-Ceramic Thin-Film Lithium-Ion Batteries Using Montmorillonite Nanosheets Electrolyte
Yuki Yoneda 1 , Shinya Suzuki 1 , Masaru Miyayama 1
1 , University of Tokyo, Hongo, Tokyo Japan
Show AbstractRecently all-ceramic lithium ion batteries have been attracting attention. In our previous study, Li-ion-conducting nanosheets have been developed by delamination of Li+-exchanged form of montmorillonite (MMT: (Na,Ca)0.3(Al,Mg)2Si4O10(OH)2･nH2O) [1]. The thin films of lithium-ion conducting MMT (Li-MMT) can be easily prepared and are chemically stable. In this research, all-ceramic thin-film lithium ion batteries were fabricated by using Li-MMT nanosheets as the solid electrolyte and those capacities and internal resistances were investigated.
All-ceramic thin-film Li ion batteries (Li4Ti5O12|Li-MMT| LiMn2O4) were fabricated in the following process. Thin-film electrodes of LiMn2O4 (cathode) (2 × 102 nm thick) and Li4Ti5O12 (anode) (3 × 102 nm thick) were fabricated on Au coated substrates by a sol-gel method as previously reported [2, 3]. Nanosheets electrolytes were deposited onto each electrode film by spin-coating the dispersion of Li-MMT. Li-MMT coated cathode and anode were attached face to face and pressed. The thickness of electrolytes was 2 μm. Charge and discharge tests and electrochemical impedance spectroscopy (EIS) were performed under a dry argon atmosphere.
The all-ceramic thin-film batteries showed a reversible capacity of 0.15 μAh at around 2.5 V. The capacity was 8.4 % of the ideal capacity measured by using liquid electrolytes. This results show that all-ceramic thin-film Li ion batteries were successfully developed using nanosheet electrolytes. The EIS of the batteries showed a high resistance component of 2 × 105 Ωcm2, which is much larger than the ion conducting resistance in the electrolyte of 2 × 103 Ωcm2. This high resistance component prevents batteries from showing the ideal capacity.
The value of the high resistance component decreased to one seventh when the lateral size of nanosheets decreases from 240 nm to 50 nm. As the nanosheets size becomes small, the nanosheets’ edge in the plane increases. It has been reported that Li ions in the Li-MMT film transport at the nanosheets’ edge when they move vertically against the film [1]. This leads to that the charge transfer reaction occurs mainly at the nanosheets’ edges in the interface between electrolytes and electrodes. Therefore, increased charge transfer of the small-sized nanosheet electrolyte is assumed to give a decrease in the resistance component.
In this study, all-ceramic thin-film Li ion batteries using nanosheets electrolytes were fablicated and showed a reversible capacity. The use of small-sized Li-MMT nanosheets was found effective to decrease the interface resistance.
References: [1] K.Otsu, S. Suzuki, M. Miyayama, Semicond. Sci. Technol., 29, 064011 (2014). [2] Y. H. Rho, K. Kanamura and T. Umegaki, J. Electrochem. Soc., 150 (1), A107 (2003). [3] Y. H. Rho, K. Kanamura and T. Umegaki, CSJ Chem. Lett., 30, 1322 (2001).
8:00 PM - ES06.03.02
Lithium Dissolution/Deposition Behavior at Li Metal/Li3PS4-LiI Electrolyte Interface for High-Temperature Operating All-Solid-State Batteries
Motoshi Suyama 1 , Atsutaka Kato 1 , Atsushi Sakuda 1 , Akitoshi Hayashi 1 , Masahiro Tatsumisago 1
1 , Osaka Prefecture University, Osaka Japan
Show AbstractLithium metal is an ultimate negative electrode to achieve a high energy density because of its extremely high theoretical capacity (3861 mAh g-1) and the lowest negative electrochemical potential (-3.045 V vs. SHE). However, the growth of lithium dendrite during lithium dissolution/deposition is a fatal problem because it leads to the formation of short-circuiting and increases the risk of fire for conventional lithium metal batteries using organic liquid electrolytes. Nonflammable inorganic solid electrolytes are attractive materials to solve the safety issues. In addition, inorganic solid electrolytes have higher thermal stability than organic liquid electrolyte and are possible to use at a high temperature above 60oC. Recently, the behavior of lithium dissolution/deposition at a high temperature has been studied. All-solid-state Li / Li7La3Zr2O12 / Li cells showed a good cycling stability of lithium dissolution/deposition at 100oC [1, 2]. On the other hand, our group has reported that Li2S-P2S5 solid electrolytes have high ionic conductivities (>10-4 S cm-1), good formability and high chemical stability against lithium metal [3, 4, 5]. Thus, Li2S-P2S5 solid electrolytes are a good candidate to fabricate lithium metal batteries. Furthermore, to improve their performance, the addition of third component to Li2S-P2S5 glass electrolytes has been studied. In particular, the ionic conductivity increased to about 10-3 S cm-1 by adding LiI to Li2S-P2S5 glass electrolyte [6]. Besides, the addition of LiI expected to suppress an undesirable side-reaction with lithium metal because of its high chemical stability against lithium metal [7]. However, the effects of the addition LiI to Li2S-P2S5 glass electrolytes on lithium dissolution/deposition properties have not been clarified.
In this study, all-solid-state Li / Li3PS4-LiI glass / Li cells were fabricated and galvanostatic cycling tests were carried out at 25oC and 100oC. The cell was able to be cycled without the formation of short-circuiting at 100oC under a higher current density compared to the operation at 25oC. To investigate the morphologies of lithium metal after lithium dissolution/deposition at 25oC and 100oC, scanning electron microscope observation was conducted. The morphologies of lithium metal after lithium deposition became more uniform at 100oC than at 25oC. The cell using 54Li3PS4-46LiI (mol%) glass was cycled at 100oC under 1.5 mA cm-2, indicating that cycling stability was drastically improved by adding LiI to Li3PS4 .
This work was financially supported by JST, the ALCA-SPRING project.
References
[1] F. Yonemoto et al., J. Power Sources, 343 (2017) 207.
[2] A. Sharafi et al., J. Power Sources, 302 (2016) 134.
[3] M. Tatsumisago et al., Solid State Ionics, 225 (2012) 342.
[4] A. Sakuda et al., Sci. Rep., 3 (2013) 2261.
[5] A. Hayashi et al., Solid State Ionics, 175 (2004) 683.
[6] R. Mercier et al., Solid State Ionics, 5 (1981) 663.
[7] Y. Zhu et al., ACS Appl. Interfaces, 7 (2015) 23685.
8:00 PM - ES06.03.03
Grain Growth in Polycrystalline Li7La3Zr2O12 Solid Electrolyte
Catherine Haslam 1 , Asma Sharafi 1 , Regina Garcia-Mendez 1 , Jeff Sakamoto 1
1 , University of Michigan, Ann Arbor, Michigan, United States
Show AbstractThe widespread adoption of electric vehicles will require batteries with energy densities beyond that of current state-of-the-art Li-ion battery technology. Although replacing state-of-the-art graphite anodes with metallic Li anodes could offer a step increase in energy density, failure caused by formation of dendrites has limited their use when paired with conventional liquid electrolytes. Thus, there is a great-unmet need for an electrolyte to stabilize metallic Li anodes. It has been shown that the solid-state electrolyte Li7La3Zr2O12 (LLZO) can stabilize the metallic Li anode while exhibiting fast ionic conductivity, electrochemical stability, and low interfacial resistance. However, at high current densities, metallic Li has been observed to propagate along grain boundaries in LLZO, causing short-circuiting. Therefore, we hypothesize that reducing the volume fraction of grain boundaries, by increasing grain size, should increase the maximum tolerable current density (critical current density, CCD) at which metallic Li propagates through LLZO. In this study, the grain size of LLZO was controlled using a combination of rapid-induction hot-pressing followed by annealing. First, the hot-pressing temperature for LLZO was optimized to give large grain size, high density, and high phase purity. Then, hot-pressed LLZO was annealed at constant temperature for various times to determine a grain growth exponent. Determination of a grain growth exponent will allow for better control of the LLZO microstructure and understanding of the LLZO grain growth mechanism. Electron backscatter diffraction was conducted on LLZO samples with different microstructures in order to determine the grain size and misorientation angle. Lastly, CCD was measured on all solid-state Li-LLZO-Li cells using DC and AC techniques to correlate CCD with grain size. Analysis of the relationship between CCD and grain size will be discussed and is intended to help elucidate the role of grain boundaries in governing Li/LLZO interface stability. This understanding is necessary to enable high CCD when using metallic Li anodes stabilized by LLZO.
8:00 PM - ES06.03.04
Interphase Formation in All-Solid-State Lithium Batteries Studied by Photoelectron Spectroscopy
Thomas Leichtweiss 1 , Wenbo Zhang 2 1 , Raimund Koerver 2 1 , Sebastian Wenzel 2 , Joachim Sann 2 1 , Wolfgang Zeier 2 1 , Juergen Janek 2 1
1 Center for Materials Research, Justus Liebig University, Giessen Germany, 2 Institute of Physical Chemistry, Justus Liebig University, Giessen Germany
Show AbstractSolid-state batteries (SSB) currently attract large interest as they promise long cycle life and inherent safety. To achieve competitive energy densities, it is necessary to apply metallic lithium as anode and a high-voltage material as cathode. [1] State-of-the-art inorganic solid electrolytes (SE) such as some thio-phosphate, NASICON-type or Li-garnet materials exhibit very high Li ion conductivities and very low electron conductivities. Despite the very promising bulk transport properties of these SE the actual performance of most reported SSB is poor. This can often be ascribed to high internal resistances at the SE-electrode interfaces which easily become rate limiting. One key issue is the electrochemical stability of both electrodes in contact with the SE: Due to the highly oxidizing potential of the cathode and the highly reducing conditions on the lithium anode side, chemical decomposition of the SE may deteriorate both contacts. The transport properties of formed interphases then determine the device performance. Recent theoretical works assess the electrochemical stability of various solid electrolytes and predict the decomposition products formed at the electrodes [2]. However, mainly due to the small thicknesses and the buried nature of the interphases, experimental investigations remain challenging.
Here, we report on the direct observation of such interphases on both electrodes by photoelectron spectroscopy (XPS). First, we focus on interphases between lithium metal and different state-of-the-art solid electrolytes by applying a novel technique which allows to follow the chemical reactions during contact formation in situ by XPS. We show that indeed most solid electrolytes are reduced in contact with Li metal and that the observed reaction products agree well with theoretical predictions. In particular, for the sulfur-based SE the formation of a reaction layer correlates with increased interfacial resistance as observed with additional time-dependent electrochemical measurements. [3]
Second, many SE are known to decompose at the highly oxidizing potential of cathode materials. We will show that XPS is a valuable tool to analyze and quantify the decomposition products formed at the interface. We will present recent results on different cathode/SE composites which undergo severe decomposition upon electrochemical cycling. [4], [5]
[1] Janek, J.; Zeier, W. (2016). Nature Energy. 1 (9), 16141. http://dx.doi.org/10.1038/nenergy.2016.141
[2] Zhu, Y., He, X., & Mo, Y. (2016). Journal of Materials Chemistry A. http://doi.org/10.1039/C5TA08574H
[3] Wenzel, S.; Randau, S.; Leichtweiss, T.; Weber, D.; Sann, J.; Zeier, W.; Janek, J. (2016). Chemistry of Materials. http://doi.org/10.1021/acs.chemmater.6b00610
[4] Koerver, R.; Dursun, I.; Leichtweiss, T; Dietrich, C.; Zhang, W.; Binder, J.; Hartmann, P.; Zeier, W.; Janek, J. (2017). Chemistry of Materials. http://doi.org/10.1021/acs.chemmater.7b00931
[5] Zhang, W.; et al. , to be submitted
8:00 PM - ES06.03.05
Quantitative Measurement of Li+ Out-Diffusion from Thin-Film Batteries by Neutron Depth Profiling
Jamie Weaver 1 , Heather Chen-Mayer 1
1 , National Institute of Standards and Technology, Gaithersburg, Maryland, United States
Show AbstractReactive sputtering is a common technique utilized in the manufacturing of all solid-state, thin-film batteries. Over the last few decades, a significant number of calculations and tests have been completed to evaluate reactive sputtering parameters and ensure the formation of durable and energy dense thin-film layered batteries. A less well studied sputtering phenomena is Li+ out-diffusion, a process in which Li+ diffuses to layers or substrates beyond the deposited battery configuration. Diffusion of Li+ out of the electrolyte and into the electrodes and/or supporting substrate can have significant impacts on ion diffusion constants as well as other parameters related to battery performance. The dearth in the literature describing Li ion out-diffusion from thin-film batteries can most likely be attributed to the limited number of techniques available to quantify Li+ diffusion without compromising the layered structure of the battery. Neutron Depth Profiling (NDP), a nuclear analytical technique, is uniquely able to meet this challenge as it is sensitive to 6Li, a naturally abundant isotope of Li. Additionally, NDP can be performed both in-situ and ex-situ to battery cycling. In this study, NDP was utilized to evaluate and quantify the extent of Li+ out-diffusion as a function of reactive sputtering parameters. Film layer thicknesses were determined by ellipsometry and SEM. Samples analyzed consisted of a simplified all thin-film layered format with LiPON as the electrolyte and variable substrate chemistries. NDP results show a yet unpublished relationship between substrate biasing during LiPON deposition and Li+ out-diffusion. Insights gathered from this study may aid in refining the measurement of the Li+ ion diffusion constants in thin-film batteries.
8:00 PM - ES06.03.06
Phase Diagram of LiF-Li3PO4 System—A New Mechanism of Heterovalent Anionic Isomorphism
Madina Sadykova 1 , Galina Zimina 1 , Maria Tsygankova 1 , Valery Fomichev 1 , Feliks Spiridonov 2 , Pavel Fedorov 3 1
1 , Moscow Technological University (MITHT), Moscow Russian Federation, 2 , Lomonosov Moscow State University, Moscow Russian Federation, 3 , Prochorov General Physics Institute Russian Academy of Sciences, Moscow Russian Federation
Show AbstractA promising basis of materials for alkaline batteries shall be the compounds with tetrahedral anions, primarily phosphates and fluorophosphates.
The phase diagram of LiF-Li3PO4 system is studied. The diagram of the eutectic type. Eutectic coordinates are 800±5 °C, 8±1 mol % Li3PO4. The melting point of lithium fluoride 845 °C, lithium phosphate has a polymorphic transition at 1175°C.
The eutectic horizontal does not reach the ordinate Li3PO4, which indicates the formation of a solid solution based on lithium phosphate. The maximum concentration of the solid solution at the eutectic temperature is 11±2 mol % LiF. According to the XRD data of the annealed samples, the limiting width of the solid solution region decreases with decreasing temperature, and is 8±1 mol % LiF at 750 °C and 6±1 mol% LiF at 600 °C. The occurrence of lithium fluoride leads to a change in the lattice parameters of γ-Li3PO4. When lithium fluoride is added to phosphate, a slight decrease in the temperature of the thermal effect corresponding to the polymorphous transformation of Li3PO4 from γ to α phase is observed. This indicates the formation of a small region of solid solution based on the high-temperature modification of α-Li3PO4. The suggested scheme of phase equilibria corresponds to metathectic equilibrium. The metathectic coordinates are 98±1 mol % Li3PO4, 1170 °C.
We assume that in the system under consideration the tetrahedral ion (PO4)3- is replaced by (LiF4)3- complex. This isomorphism scheme is described by the following reaction:
(1-x)Li3PO4+4xLiF → Li3(PO4)1-x(LiF4)x
Thus, the presented study results suggest the formation of solid solution based on lithium phosphate as a result of the entry into the crystalline structure of the coordination tetrahedron (LiF4)3-, substituting (PO4)3- anion. Such substitution is a new mechanism of anionic heterovalent isomorphism.
8:00 PM - ES06.03.07
Novel Argyrodite-Type Sulfide Solid Electrolytes Synthesized via a Liquid-Phase Process for All-Solid-State Lithium Batteries
So Yubuchi 1 , Atsushi Sakuda 1 , Akitoshi Hayashi 1 , Masahiro Tatsumisago 1
1 , Osaka Prefecture University, Sakai, Osaka Japan
Show AbstractRecently, it has been reported that sulfide solid electrolytes such as Li7P3S11 glass-ceramic and Li9.54Si1.74P1.44S11.7Cl0.3 crystal showed so high lithium-ion conductivities of more than 10 mS cm-1 and all-solid-state batteries with great electrochemical properties were fabricated [1]. However, for practical application, the electrolytes with wide electrochemical windows are also required. Argyrodite-type sulfide electrolytes Li7-yPS6-yXy (X = Cl, Br) have the high electrochemical stabilities. In addition, we have reported a liquid-phase synthesis as a novel versatile approach of Argyrodite-type sulfide electrolytes [2]. We have also reported that the solid-solid interfaces between electrodes and solid electrolytes in composited electrodes were easily formed by this liquid-phase technique. On the other hand, the relationship between high conductivities and ionic radii of the substituted anions X in Argyrodite-type electrolytes has been reported [3].
In this study, novel Argyrodite-type sulfide solid electrolytes substituted by monovalent polyatomic anions such as NO3- and BH4- were synthesized by a liquid-phase technique, and then the relationship between the ionic radii of the substituted anions and the conductivities was investigated. In addition, the all-solid-state cells using Argyrodite-type solid electrolytes prepared via a liquid-phase process were fabricated.
Li6PS5X (X = Cl, NO3, Br, BH4 and I) solid electrolytes were synthesized from Li3PS4 glass, Li2S and LiX (X = Cl, NO3, Br, BH4 and I) using ethanol. Fine powders were precipitated after removing the solvents by drying at 150oC. The obtained samples were mainly Argyrodite-type crystals. In particular, novel Argyrodite-type Li6PS5X (X = NO3, BH4) were successfully prepared. The composition dependence of the lattice constants in the Argyrodite-type crystals was proportional to the ionic radii of the substituted anions. The Li6PS5X (X = Cl, NO3, Br, BH4 and I) electrolytes respectively showed the ionic conductivities of 0.16, 0.054, 0.18, 0.021 and 0.11 mS cm-1. In addition, Li6PS5Br electrolyte showed an ionic conductivity of 1.1 mS cm-1 at 25oC by heat treatment at 550oC.
The cell with the mixtures of the obtained Li6PS5Br and LiNi1/3Mn1/3Co1/3O2 (NMC) particles showed the capacity of 150 mAh g-1. Moreover, the Li6PS5Br solid electrolytes were coated on NMC particles using the solution and then the bulk-type all-solid-state cells using Li6PS5Br-coated NMC were fabricated. The cells using only Li6PS5Br-coated NMC as a positive electrode showed higher reversible capacity than those using a conventional mixture of NMC and Li6PS5Br powders.
[1] A. Hayashi et al., Front. Enegy Res., 4 (2016) 1.
[2] S. Yubuchi et al., J. Power Sources, 293 (2015) 941.
[3] P. R. Rayavaraou et al., J. Solid State Electrochem., 15 (2012) 1807.
8:00 PM - ES06.03.08
High-Performance All-Inorganic Solid-State Na-S Battery Enabled by Na3PS4-Na2S-C Nanocomposite Cathode
Jie Yue 1 , Fudong Han 1 , Xiulin Fan 1 , Chunsheng Wang 1
1 , University of Maryland, College Park, College Park, Maryland, United States
Show AbstractAll-solid-state sodium sulfur batteries using sulfide-based solid electrolyte suffer from low sulfur utilization, poor cycle life and low rate performance mainly due to the huge electrode/electrolyte interfacial resistance arising from the insufficient triple-phase contact among sulfur active material, ionic conductive solid electrolyte, and electronic conductive carbon. Here we present our approaches to address the interfacial problem by using Na3PS4-Na2S-C (carbon) nanocomposite as the cathode for all-solid-state sodium-sulfur batteries. Highly ionic conductive Na3PS4 contained in the nanocomposite can function as both solid electrolyte and active material (catholyte) after mixing with electronic conductive carbon, leading to an intrinsic superior electrode/electrolyte interfacial contact because only a two-phase contact is required for the charge transfer reaction. Introducing nano-sized Na2S into the nanocomposite cathode can effectively improve the capacity. The homogeneous distribution of nano-sized Na2S, Na3PS4 and carbon in the nanocomposite cathode could ensure a high mixed (ionic and electronic) conductivity and a sufficient interfacial contact, which enabled significantly-improved battery performances.
8:00 PM - ES06.03.09
Effect of Graphene Oxide as Reinforcement Phase in Oxide-Based Lithium-Ion Conductors
Maria Ramirez 1 , Mok Yun Jin 1 , Ravi Kumar 1 , Brian Sheldon 1
1 , Brown University, Providence, Rhode Island, United States
Show AbstractThe relatively low fracture toughness of ceramic solid electrolytes can significantly limit battery performance and reliability. While small dimensions are generally needed for faster ion transport, these length scales also restrict the approaches that can be used to improve fracture resistance. Nanoscale reinforcements are thus a logical option for improving the fracture resistance of ceramic electrolytes. Graphene oxide and reduced graphene oxide have been successfully used to reinforce a variety of polymer and engineering ceramics, where significant changes in the elastic modulus and toughness have been obtained with relatively low volume fractions. In the present work, we explore the reinforcement capability of small amounts of graphene oxide added to oxide-based lithium ion conductor such as LLZTO. Fracture toughness measurements and electrochemical impedance were employed to obtain information on both the mechanical response and ionic conductivity of composites consolidated by spark plasma sintering.
8:00 PM - ES06.03.10
Suppression of Binder Resistance for Cathode Electrode with Pre-Clustering in All-Solid-State Batteries Using Sulfide Based Solid Electrolyte
Sungwoo Noh 1 , Moonju Cho 1 , Chan Hwi Park 1 , Dongwook Shin 1
1 , Hanyang University, Seoul Korea (the Republic of)
Show AbstractLithium ion batteries are common in portable electronic devices because they have high energy density and long cycle life. Recently, large-scale lithium-ion batteries for electric vehicles have attracted much attention, but commercialization has been hampered due to concerns about the safety of batteries employing conventional organic liquid electrolytes. The safety issues of the liquid electrolyte are mainly caused by chemical reactions with the active cathode materials at elevated temperature, electrolyte leakage and a narrow electrochemical window. As a result, considerable efforts have been focused on developing all-solid-state lithium ion batteries. However, electrochemical performance of film electrode is deteriorated because of blocked charge transfer due to direct contact interference from the binder. Therefore, It is necessary to minimize the influence of the binder. To address this issue, specific surface area of composite cathode were changed by pre-clustering the composite cathode. In addition, PTFE powder was added to increase the effect of pre-clustering to improve the electrochemical performance. In this research, correlation between the specific surface area of composite cathode and the electrochemical performance of electrode was investigated. Surface area of composite cathode were controlled via pre-clustering process. Specific surface area were determined by Brunauer−Emmett−Teller (BET) method. Cathodes electrode of all-solid-state batteries were produced tape casting process. All-solid-state cells were constructed by uniaxial cold pressing method. Microstructure and electrochemical properties of fabricated all-solid-state cells with different specific surface area of composite cathode were characterized.
Specific surface area of composite cathode showed drastically decrease after pre-clustering process. Morphology of pre-clustered composite cathode shows agglomeration shape. Electrochemical performance of prepared all-solid-state cells shows that pre-clustered samples showed better electrochemical performance. Therefore, Improved electrochemical performances of pre-clustered samples are indicating that binder in cathode electrode act as large resistance in all-solid-state batteries.
8:00 PM - ES06.03.11
Electrochemical Properties of Thick Film Composite Cathode Fabricated by Electrostatic Slurry Spray Deposition Technique for All-Solid-State Li-Ion Batteries
Chan Hwi Park 1 , Jinoh Son 1 , Sewook Lee 1 , Dongwook Shin 1
1 , Hanyang University, Seoul Korea (the Republic of)
Show AbstractThe demand of large scale Li-ion batteries for power sources such as electric vehicles (EV) and energy storage systems (ESS) is increasing. Most Li-ion batteries are composed of two electrode layers and a polymer separator with a liquid electrolyte. However, the conventional Li-ion batteries with liquid electrolytes have been reported of some safety issues by its flammability. To resolve the safety issues, all-solid-state Li-ion batteries have been considered for a candidate of next generation Li-ion batteries. The key material to realize all-solid-state Li-ion batteries is solid electrolytes with high ionic conductivity and safety.
Several types of sulfide based solid electrolytes have been shown favorable Li-ion conductivities of 10-3-10-2 S/cm, which are comparable to those of liquid electrolytes, have been reported. In addition, those have many advantages of a single Li-ion conductor and provide excellent electrochemical stability over a wide potential range.
However, the all-solid-state batteries have a disadvantage of lower energy density than the conventional batteries using a liquid electrolyte. The inorganic solid electrolyte has a smaller contact area with the active electrode material than the liquid electrolyte, thereby limiting the ionic paths in the composite cathode, and exhibiting a low electrochemical performance in the all-solid-state batteries. It is important to fabricate a composite cathode which achieves continuous Li-ion and electron conducting paths composed of a solid electrolyte and a cathode active materials, a conducting agent. In a large number of reports, composite cathodes were prepared by dry mixing but it is very difficult to produce a homogeneous powder distribution. As a result, it demonstrated low electrochemical performance in all-solid-state batteries.
In the present study, the LiCoO2/Li2S-P2S5 electrolyte composite cathode was successfully fabricated by the ESSD (Electrostatic Slurry Spray Deposition) technique to obtain the homogeneous thick film composite electrode. The ESSD technique uses electrical energy to atomize and spray the slurry containing prepared powders. And it is easy to fabricate dense thick film with homogeneous distribution and no cracks.
Composite cathodes were fabricated with different cathode material / solid electrolyte ratio. Solid electrolytes were synthesized by mechanical milling method. The distribution of the deposited composite cathode thick films was investigated by SEM and EDX. In addition, we made all-solid-state Li-ion batteries with composite cathode / solid electrolyte / In metal foil structure by uniaxial cold pressing method. All-solid-state batteries have been successfully tested for electrochemical performance.
8:00 PM - ES06.03.12
Liquid-Phase Synthesis of Na3PS4 Solid Electrolyte Using Ethers
Miwa Uematsu 1 , So Yubuchi 1 , Atsushi Sakuda 1 , Akitoshi Hayashi 1 , Masahiro Tatsumisago 1
1 , Osaka Prefecture University, Sakai Japan
Show AbstractAll-solid-state batteries using nonflammable inorganic solid electrolyte are more safe and reliable than ordinary batteries using organic electrolyte. In addition, sodium secondary batteries are attracting attention because sodium is abundant and inexpensive resource. We have reported that sulfide glass-ceramics of cubic Na3PS4 prepared by mechanical milling show the high sodium-ion conductivity of over 10-4 S cm-1 at room temperature [1]. All-solid-state batteries using the solid electrolyte successfully worked as secondary batteries at room temperature. For a practical realization of all-solid-state batteries, more simple methods of preparing solid electrolyte are required. Recently, a liquid-phase synthesis of solid electrolytes is attracting attention. In this method, raw materials are stirred in organic solvents, and obtained suspensions or solutions are dried and heated to obtain solid electrolytes. This method is suitable for practical application because it is highly versatile and can control particle morphology. However, favorable reaction conditions of liquid-phase syntheses of solid electrolytes have not been clarified. There is only one report about sulfide sodium-ion conductors prepared from raw material by a liquid-phase method [2]. In this study, Na3PS4 solid electrolytes were prepared via a liquid-phase process using diethyl ether or 1,2-dimethoxyethane (DME) and its structure and ionic conductivities were evaluated.
Na3PS4 solid electrolytes were synthesized from Na2S and P2S5 by stirring in diethyl ether or DME. The obtained suspensions were dried at room temperature to get precursor powders. The precursors were heated at 270oC under vacuum. The obtained powders were uniaxially pressed at 360 MPa or 720 MPa into pellets for AC impedance measurements.
The powders heated at 270oC were mainly identified as cubic Na3PS4. In the case of using diethyl ether, particles of 5 to 100 mm were obtained and its conductivity was 2.9 x 10-5 S cm-1 at 25oC. When DME was used, fine particles of several 100 nm or less were obtained and its ionic conductivity was 1.2 x 10-5 S cm-1. Cross-sectional SEM images indicated that the pellet of Na3PS4 prepared diethyl ether was very dense. On the other hand, there were many pores of several mm in size in the pellet of the sample prepared using DME. A hot-pressed pellet showed higher density and higher ionic conductivity of 2.6 x 10-5 S cm-1. The sodium-ion conductivities of Na3PS4 prepared here were higher than the conductivity of 10-6 S cm-1 previously reported [2].
[1] A. Hayashi et al., Nat. Commun., 3 (2012) 856.
[2] S. Yubuchi et al., Chem. Lett., 44 (2015) 884.
8:00 PM - ES06.03.13
Mechanical Behavior of Sulfide Solid Electrolytes for Lithium-Ion Batteries—From Brittle to Ductile
Shilpa Raja 1 , Frank McGrogan 1 , Tushar Swamy 1 , Han Nguyen 2 , Wolfgang Zeier 3 , Juergen Janek 3 , Y. Shirley Meng 2 , Yet-Ming Chiang 1 , Krystyn Van Vliet 1
1 , Massachusetts Institute of Technology, Cambridge, Massachusetts, United States, 2 , University of California, San Diego, San Diego, California, United States, 3 , JLU Geissen, Geissen Germany
Show AbstractLithium ion batteries (LIBs) are a key energy storage technology, due to their low weight and high energy density. However, LIBs comprising liquid electrolytes include limitations such as flammability, poor ion selectivity, and poor temperature stability that are attributed in part to the potential shorting via dendritic growth through the liquid spanning the solid electrode materials. Solid-state batteries comprising solid electrolytes (SEs) have the potential to ameliorate these issues by providing higher energy and power densities, improved thermal stability and safety, and good ion selectivity. Sulfide SEs, in particular the thio-LISICON system consisting of lithium thiophosphate (Li3PS4, LPS) and its derivatives, such as Li10GeP2S12 (LGPS), have been found to be among the most promising. This is due to the high conductivities and ability to be pressed to high densities (>95%) of such SEs at room temperature, enabling room-temperature battery assembly.
Solid electrolytes also present new challenges, due to the mechanical stiffness and potential for stresses developed within the electrolyte and at electrolyte/electrode interfaces during electrochemical cycling. Thus, the elastic, plastic, and fracture properties of SEs are of critical importance to predict and mitigate potential for fracture within or between these solid phases. However, the characterization of such key mechanical properties remains limited, including a recent report on one sulfide SE, Li2S-P2S5, which was of low stiffness and low fracture toughness relative to other potential SEs and electrode active materials [1]. Here we report the Young’s modulus, hardness, and fracture toughness for a range of sulfide SE systems, including ß-LPS, LGPS, Li6PS5Cl, Li10SnP2S12 (LSPS) and others. Our study includes systems known for low cost and ease of scalability, with measured conductivities as high as 11 mS/cm. While these sulfide SEs exhibited similar elastic properties, they exhibited a wide range of plastic and fracture properties that included the potential for ductility and fracture toughness far exceeding the brittle, low toughness characteristics of Li2S-P2S5. We discuss the correlation of these key mechanical properties with ionic conductivity, and implications for design of both flaw tolerant SEs and mechanically robust solid-state batteries.
1. McGrogan, Frank P., et al. "Compliant Yet Brittle Mechanical Behavior of Li2S–P2S5 Lithium Ion Conducting Solid Electrolyte." Advanced Energy Materials (2017), DOI: 10.1002/aenm.201602011
8:00 PM - ES06.03.14
A New, Air-Stable Na3SbS4 Solid Electrolyte for All-Solid-State Sodium Batteries
Zachary Hood 1 2
1 , Georgia Institute of Technology, Atlanta, Georgia, United States, 2 , Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States
Show AbstractAll-solid-state sodium batteries, those that utilize solid electrolytes and abundant sodium resources, show great promise for safe, low-cost, and large-scale energy storage applications. To achieve more-efficient all-solid-state sodium batteries, the exploration of novel highly conductive solid electrolytes is critical for room temperature operation. Ideal solid electrolytes for sodium batteries must have high ionic conductivity, employ low-cost synthetic methods, and hold outstanding chemical and electrochemical stability. Achieving the combination of these properties represents a grand challenge for most sulfide-based solid electrolytes. Herein, we report the design of a new solid electrolyte, Na3SbS4, which realizes excellent air stability and can be prepared through an economic synthesis centered on hard and soft acid and base (HSAB) theory. This new sodium-ion solid electrolyte exhibits a remarkably high ionic conductivity of 1 mS cm−1 at 25 °C and is also demonstrated to cycle with a metallic sodium anode in a symmetric cell configuration.
References:
1. Liu, Jun, et al. Advanced Functional Materials 23.8 (2013): 929-946.
2. Pan, Huilin, Yong-Sheng Hu, and Liquan Chen. Energy & Environmental Science 6.8 (2013): 2338-2360.
3. Hueso, Karina B., Michel Armand, and Teófilo Rojo. Energy & Environmental Science 6.3 (2013): 734-749.
4. Wang, Hui, Yan Chen, Zachary D. Hood, Gayatri Sahu, Amaresh Samuthira Pandian, Jong Kahk Keum, Ke An, and Chengdu Liang. Angewandte Chemie International Edition 55, no. 30 (2016): 8551-8555.
8:00 PM - ES06.03.15
Solid State Lithium Thin-Film Battery Composed of Li4Ti5O12 Anodes with a Solid Garnet Li6.25Al0.25La3Zr2O12 Electrolyte
Reto Pfenninger 1 2 , Semih Afyon 2 , Michal Struzik 2 1 , Inigo Garbayo 2 , Jennifer Rupp 2 1
1 , MIT, Cambridge, Massachusetts, United States, 2 D-MATL, ETH Zürich, Zurich Switzerland
Show AbstractNext generation energy storage devices for stationary and mobile electronics will not only need high gravimetric and volumetric capacity, but also long term stability even in rough environments and at elevated temperature. Going all-solid-state opens up completely new pathways for chip integration and downscaling to the sub-micron range for high energy densities to battle supercapacitors. From a materials perspective, cubic garnet Li7La3Zr2O12-based structures are among the fastest conducting solid state electrolytes1. Moreover, their inherent compatibility with Lithium in the form of metal, their stability in a wide voltage range as well as their Arrhenius-activated conduction mechanism support their prospering interest for all solid state large-scale and future microbatteries. Despite the promise, only few attempts have been conducted to test thin film electrodes in conjunction with cubic garnet Li7La3Zr2O12, namely work by Ohta2 which focused on thin-film LiCoO2 or van den Broek3 whose approach was based on slurry-casting of anode material on bulk pellet Li7La3Zr2O12. However, literature reports of PLD deposited thin films of anode materials in combination with Li7La3Zr2O12, remain rare. In particular, Li4Ti5O12 is known as one of the most stable anode material due to its remarkably low volume expansion upon lithiation/delithiation and its good cycle performance4. In this work, we report our latest progress on nanostructuring different promising anode thin films of Li4Ti5O12 deposited by pulsed laser deposition and for constructed bilayer half cell battery systems with Li7La3Zr2O12 pellets as the electrolyte. Rate capability studies as well as galvanostatic cycling of this system showed promising initial capacity and acted as a case study for the well-known Li4Ti5O12 thin film anode, showing its good compatibility with the investigated solid garnet electrolyte. Capacitites of 150 mAh/g, which corresponds to almost the theoretical capacity of this material (175 mAh/g) could be achieved with stable cycling at different rates. Near-order phenomena could be tracked by Raman spectroscopy and gave insight into the process of thin film growth by pulsed laser deposition (PLD). Good adhesion between the thin film and the bulk pellet opens up for promising future application of thin film deposited anodes for future microbattery applications.
Reference
1.Thangadurai, V., Narayanan, S. & Pinzaru, D. Chem. Soc. Rev. 43, 4714 (2014).
2.Ohta, S., Kobayashi, T., Seki, J. & Asaoka, T. J. Power Sources 202, 332–335 (2012).
3.van den Broek, J., Afyon, S. & Rupp, J. L. M. Adv. Energy Mater. 1600736 (2016). doi:10.1002/aenm.201600736
4.Kumatani, A. et al. Appl. Phys. Lett. 101, 123103 (2012).
8:00 PM - ES06.03.16
All Solid-State Lithium Battery Using LISICON Electrolyte
Sou Taminato 1 , Toyoki Okumura 1 , Tomonari Takeuchi 1 , Hironori Kobayashi 1
1 , Advanced Industrial Science and Technology, Ikeda Japan
Show AbstractOxide electrolytes have lower sensitivity to moisture and toxicity when compared to sulfide electrolyte, and are anticipated to improve the reliability in the battery system. However, it has challenge to construct the well-formed electrode-electrolyte composite electrode, which usually shows large contact resistance for ion transfer at the electrode/electrolyte interface, due mainly to their poor deformability at room temperature. Although sintering process is needed to make good contact between electrode and electrolyte, lower temperature sintering is desirable to avoid the formation of resistive interfacial phases [1]. Lithium superionic conductor (LISICON) related material, Li3.6Ge0.8S0.2O4 shows approximately 10-5 S/cm at room temperature, and could be co-sintered with the electrode materials at lower temperature than the well-known high ionic conductive oxides, such as garnet and perovskite type structure, which required over 1000°C by conventional sintering (CS) process using the electric furnace. Recently, we have reported that well-defined interface between electrode and electrolyte without any impurity phases were achieved by spark plasma sintering (SPS) process, which enhanced the reversible capacity of the all solid-state cell when compared to that by CS process [2]. In this study, the all solid-state battery using LISICON related oxide, Li3.6Ge0.8S0.2O4 as electrolyte material is assembled by SPS process and investigated the charge-discharge performance.
The powder XRD patterns of the prepared Li3.6Ge0.8S0.2O4 was identified to the LISICON phase with γ-Li3PO4 type structure reported previously [3]. Total conductivity of the sample sintered at 600°C by SPS process was 2×10-5 S/cm at room temperature, which is comparable to that at 800−1100°C by CS process. This demonstrates that SPS process successfully sintered Li3.6Ge0.8S0.2O4 at lower temperature than that by CS process. The all solid-state cell (LiNi0.33Mn0.33Co0.33O2-Li3.6Ge0.8S0.2O4 composite cathode/Li3.6Ge0.8S0.2O4 electrolyte/dry polymer/lithium foil) assembled by SPS process at 600°C exhibited a first discharge capacity of 130 mAh g-1 between 2.0 and 4.2 V (vs. Li/Li+) under a constant current of 32 µA/cm2 at 60°C. The charge-discharge characteristics of the cell assembled by SPS process will be discussed compared to that by CS process based on the microstructural and electrochemical results.
(References)
[1] J. Xie, N. Imanishi, T. Zhang, A. Hirano and Y. Takeda, J. Power Sources, 189, 365–
370 (2009).
[2] T. Okumura, T. Takeuchi and H. Kobayashi, J. Ceram. Soc. Jpn, 125(4), 276-280
(2017).
[3] M.A.K.L. Dissanayake, R.P. Gunawardane, A.R. West, solid State Ionics, 62, 217–
223 (1993).
(Acknowledgements)
This work was financially supported by the Advanced Low Carbon Technology Research and Development Program of the Japan Science and Technology Agency for Specially Promoted Research for Innovative Next Generation Batteries (JSTALCA SPRING).
8:00 PM - ES06.03.17
Protected Lithium Metal Enabling All-Solid-State Lithium-Ion Batteries with High Energy Density
Changhong Wang 1 , Xueliang Sun 1
1 , University of Western Ontario, London, Ontario, Canada
Show AbstractAll-solid-state lithium ion batteries (ASSLIBs) have aroused intensive studies recently due their outstanding merits in safety and energy density, which are mandatory requirements of electric vehicles and large-scale energy storage. As an essential component in ASSLIBs, solid electrolytes have already shown comparable ionic conductivity with that of liquid electrolytes, especially sulfide electrolytes, implying their great potential in the application of ASSLIBs. However, sulfide electrolytes are thermodynamically unstable against lithium metal, which is regarded as the ultimate anode material of lithium batteries by reason of its lowest chemical potential (-3.040 V vesus the standard hydrogen electrode) and the high theoretical capacity (3680 mAh.g-1 or 2061 mAh.cm-3).1 To improve the stability between sulfides and lithium metal, two main approaches have been proposed: (i) lithium alloys (e.g. Li-In alloy) are commonly used as the anode of ASSLIBs.2 However, extremely expensive indium is impractical for large scale application. In addition, the energy density of ASSLIBs based on lithium alloys is reduced because of the elevated chemical potential of lithium alloys (Li-In, 0.62 V vs Li+/Li). (ii) doule layers electrolytes are exploited, in which a stable solid electrolyte is put toward lithium metal to stablize the anode interface.3 However, this approach could also reduce the energy density and increase the troulbe in the industrial engineering of ASSLIBs. Under this scenario, it is highly desired and extremely urgent to develop new strategies to stablize the anode interface between sulfide electrolytes and lithium metal for the application of ASSLIBs.
In this work, a few nanometers polymeric alucone was coated on the surface of lithium metal by a molecular layer deposition (MLD) technique. As a result, the overpotential of lithium plating/stripping is minimized and its cyclability is also doubled once the lithium is coated with alucone. Compared with bare lithium-based all-solid-state lithium batteries, the alucone-coated lithium-based ones show smaller internal resistance, more stable cyclability, and a higher discharge plateau. Confirmed by the results of XPS and RBS, a few nanometers polymeric alucone on the surface of lithium metal serves as an artificial solid electrolyte interphase (SEI), which suppresses the interfacial reactions between sulfide electrolytes and lithium metal. Furthermore, the flexible polymeric alucone can accommodate the strain/stress induced by the volume change upon cycling, thus benefiting the long-term cyclability of ASSLIBs.
References
1. D. Lin, Y. Liu and Y. Cui, Nat. Nano, 2017, 12, 194-206.
2. Y. Kato, S. Hori, T. Saito, K. Suzuki, M. Hirayama, A. Mitsui, M. Yonemura, H. Iba and R. Kanno, Nature Energy, 2016, 1, 16030.
3. X. Yao, D. Liu, C. Wang, P. Long, G. Peng, Y.-S. Hu, H. Li, L. Chen and X. Xu, Nano Lett., 2016.
8:00 PM - ES06.03.18
Understanding the Role of Grain Boundaries in Controlling the Li Metal - Li6.25Al0.25La3Zr2O12 (LLZO) Solid Electrolyte Interface During DC Cycling
Regina Garcia-Mendez 1 , Jeff Sakamoto 1
1 , University of Michigan, Ann Arbor, Michigan, United States
Show AbstractThe demand for vehicle electrification has created the impetus to develop energy storage technology beyond Li-ion. One approach involves the use solid electrolytes to enable metallic Li anodes, pushing energy densities > 1000 Wh/l. However, the ability to plate Li metal at relatively high current densities (> 3 mA/cm2), has not been demonstrated using solid electrolytes. Moreover, it was reported [1] that in polycrystalline solid electrolyte such as Li6.25Al0.25La3Zr2O12 (LLZO), Li preferentially deposits intergranularly. We hypothesize that the maximum Li plating rate (or critical current density – CCD) is strongly correlated to the existence of microstructural defects, such as grain boundaries, as initiation points for Li metal propagation. In this work, the role that grain boundaries play in initiating Li metal propagation was studied. DC measurements as a function of current density and evolution of the AC impedance spectra were analyzed to characterize the effects of Li metal penetration above the CCD. The results obtained from this work provide a more comprehensive understanding of the role that microstructural defects, specifically grain boundaries, play in controlling Li plating rates. The knowledge gained will help engineer solid electrolyte microstructures to enable all-solid state batteries using metallic Li anodes.
Reference:
[1] Cheng, E. J., Sharafi, A., & Sakamoto, J. (2017). Intergranular Li metal propagation through polycrystalline Li 6.25 Al 0.25 La 3 Zr 2 O 12 ceramic electrolyte. Electrochimica Acta, 223, 85-91.
8:00 PM - ES06.03.19
Microstructure Evolution in Li-Free Thin-Film Solid-State Li-Ion Batteries
Heng Yang 1 , Xiaoxing Xia 1 , Michael Citrin 1 , Simon Nieh 2 , Julia Greer 1
1 , California Institute of Technology, Pasadena, California, United States, 2 , Front Edge Technology, Inc., Baldwin Park, California, United States
Show AbstractLi-ion thin film solid state batteries are capable of battery life of more than 10000 cycles1. “Li-free” anodes in solid-state batteries eliminate lithium metal in the manufacturing stage, which could improve energy density, simplify manufacturing process, and lower cost. Attempts to fabricate “Li-free” cells have been challenging because of the concomitant reduction in cycle stability2, 3. Replacing the Cu current collector with metals like Au and Pt, which alloy with Li, shows mild improvement in cycle stability, probably because it creates a more stable interface4-6.
We fabricate LiCoO2 (20 μm)/LiPON (3 μm)/M (20 nm) thin film solid state cells, where M is Cu, Au, or Si, and study the electrochemical properties and microstructure changes within each thin film during cycling using an in-situ SEM. We investigate the nucleation, growth and stripping of lithium at the solid electrolyte/current collector interface and monitor the interactions of these elements with lithium. We correlate these microstructural details with coulombic efficiency and cycle stability of lithium. These results provide insights into the fundamental electrochemistry and microstructure evolution that occurs in thin film solid-state Li-ion batteries during cycling and may have significant impact on developing “Li-free” solid-state batteries.
1. J. Li, C. Ma, M. Chi, C. Liang and N. J. Dudney, Advanced Energy Materials, 2015, 5, 1401408-n/a.
2. J. B. Bates, N. J. Dudney, B. Neudecker, A. Ueda and C. D. Evans, Solid State Ionics, 2000, 135, 33-45.
3. B. J. Neudecker, N. J. Dudney and J. B. Bates, J. Electrochem. Soc., 2000, 147, 517-523.
4. M. Motoyama, M. Ejiri and Y. Iriyama, J. Electrochem. Soc., 2015, 162, A7067-A7071.
5. A. Kato, A. Hayashi and M. Tatsumisago, J. Power Sources, 2016, 309, 27-32.
6. K. Okita, K.-i. Ikeda, H. Sano, Y. Iriyama and H. Sakaebe, J. Power Sources, 2011, 196, 2135-2142.
8:00 PM - ES06.03.20
Novel Analysis of Solid State Electrolytes on Lithium Metal Battery
Gahee Kim 1 2
1 Analysis Science Group, Samsung Advanced Institute of Technology, Suwon Korea (the Republic of), 2 , Samsung Electronics Company, Suwon Korea (the Republic of)
Show AbstractLithium metal batteries are the most promising candidates for next generation portable devices where higher energy density is necessary. However, dendrite growth on top of Li anode that has highest energy efficiency hinders practical application of lithium metal batteries. In this regards, employment of protecting layers such as tough membranes or solid electrolytes can be candidates to inhibit dendrite growth and to achieve a long-life cycling performance. Herein, we propose a novel analytical method that measures shear strength of the protecting layer in the out-of-plane direction. Since the lithium dendrite grows in the vertical direction from the anode surface, the shear modulus in the thickness direction of the protective film is an indispensable method. In particular, the stress can be calculated from the axial force that is measured by a fixed solid probe during thermal expansion. Similarly, the thickness change is measured directly from the thermal expansion. The obtained stress and strain can also be converted to shear modulus. This method is applied to a series of poly vinyl alcohol (PVA) thin protecting layers of varying salt contents. The expansion force and thickness change are measured to be reduced with the increase of salt ratio for declining in the elasticity of the thin layers. Initial capacity and cycle performance of lithium metal batteries with PVA protecting layer are improved proportionally with the increase of stress and strain. The newly introduced analytical method demonstrates the measurements of mechanical properties in the thin protecting layer relevant to the direction of dendrite growth.
Symposium Organizers
Yan Wang, Worcester Polytechnic Institute
Chang-Jun Bae, Korea Institute of Materials Science
Juergen Janek, Justus-Liebig Univ-Giessen
Jun Wang, A123 Systems, LLC
ES06.04: Solid Electrolyte III
Session Chairs
Tuesday AM, November 28, 2017
Hynes, Level 2, Room 203
8:30 AM - *ES06.04.01
Machine Learning and High-Throughput Experimental Tools for Advancing Ionics
Sossina Haile 1 , Ruiyun Huang 1 , Timothy Davenport 1 , Yangang Liang 2 , Xiaohang Zhang 2 , Ichiro Takeuchi 2 , Erin Antono 3 , Greg Mulholland 3
1 , Northwestern University, Pasadena, California, United States, 2 MSE, University of Maryland, College Park, Maryland, United States, 3 , Citrine Informatics, Redwood City, California, United States
Show AbstractDevelopment of materials with enhanced ionic conductivity in combination with, for example, high mechanical strength, excellent chemical stability, and either very low or comparable electronic conductivity, remains a critical need for a range of energy technologies. The vast literature in this area, built over decades of study, has provided important insights into the governing chemistry-structure-properties relationships, yet even better, as-yet unpredicted materials, remain desirable. Here we describe an approach for new materials discovery that combines machine learning, drawing on hundreds of published studies, and targeted high throughput experimentation, focused on the most promising candidates identified from the first step. Lessons learned about the most important crystal chemical parameters impacting conductivity are discussed in the context of conventional wisdom in the field of solid state ionics.
9:00 AM - ES06.04.02
Protons Enhance Conductivities in Lithium Halide Hydroxide/Lithium Oxyhalide Solid Electrolytes by Forming Rotating Hydroxy Groups
Ah-Young Song 1 , Yiran Xiao 1 , Kostiantyn Turcheniuk 1 , Punith Upadhya 1 , Anirudh Ramanujapuram 1 , Jim Benson 1 , Alexandre Magasinski 1 , Marco Olguin 2 , LaMartine Meda 3 , Oleg Borodin 2 , Gleb Yushin 1
1 , Georgia Institute of Technology, Atlanta, Georgia, United States, 2 , U.S. Army Research Laboratory, Adelphi, Maryland, United States, 3 , Xavier University of Louisiana, New Orleans, Louisiana, United States
Show AbstractLi halide hydroxides (Li2OHX) and Li oxyhalides (Li3OX) have emerged as new classes of low-cost, lightweight solid state electrolyte (SSE) compounds showing promising Li-ion conductivities.[1] However, their typical syntheses often bring contaminations and uncontrollable escape of volatiles.[2] In addition, the similarity in the lattice parameters between Li2OHX and Li3OX combined with insufficient rigor in material characterization often lead to erroneous interpretations of the reported material compositions. Finally, moisture remaining in the synthesized products or cell assembling environment, leaks in the electrochemical cells and variability in the equivalent circuit models may additionally contribute to significant errors in the reported properties. Thus, there remains is a controversy about the real values of Li-ion conductivities in these SSEs. Here, we present an ultra-fast synthesis and comprehensive material characterization methods and ionic conductivities of contaminant-free Li2OHCl, Li2.1OH0.9Cl, Li2.4OH0.6Cl, Li2.7OH0.3Cl and Li2OHBr. Using a powerful combination of experimental and numerical approaches, we demonstrate that the presence of H in these SSEs yields significantly higher Li+ ionic conductivity. Born-Oppenheimer molecular dynamics (BOMD) simulations showed excellent agreement with experimental results and revealed an unexpected mechanism for faster Li+ transport. It involves rotation of a relatively short OH-group within the SSEs, which opens lower-energy pathways for the formation of Frenkel defects and highly-correlated Li+ jumps. We anticipate that our findings will reduce the existing confusions and show new avenues for tuning SSE compositions for further improved Li-ion conductivities. This work were supported by NASA Minority University Research and Education Project (MUREP; NASA grant NNX15AP44A and interagency agreement NND16AA29I with ARL for modeling) and ARPA-E (grant DE-AR0000779).
References:
[1] Z. Deng, B. Radhakrishnan, S. P. Ong, Chemistry of Materials, 2015. 27: p. 3749.
[2] Y. Zhao, and L.L. Daemen, J Am Chem Soc, 2012. 134(36): p. 15042-7.
[3] A.-Y. Song, Y. Xiao, K. Turcheniuk, P. Upadhya, A. Ramanujapuram, J. Benson, A. Magasinski, M. Olguin, L. Medab, O. Borodin, and G. Yushin, Advanced Energy Materials, 2017. in press.
9:15 AM - *ES06.04.03
Solution Processed Conformal Solid Electrolyte Layers
Hee-Dae Lim 1 , Xing Xing 1 , Ping Liu 1
1 , University of California, San Diego, La Jolla, California, United States
Show AbstractSolid electrolyte and all-solid-state batteries have attracted great attentions as a next generation battery system because they have potential to solve the safety issues in lithium ion batteries (LIBs) as well as enable lithium metal to cycle reversibly. Thus far, many kinds of solid electrolytes have been investigated and demonstrated to deliver high conductivities, and especially, sulfide-based electrolyte have shown a superior conductivity even comparable to the conventional liquid electrolyte (Li10GeP2S12: 12 mS/cm [1], Li7P3S11: 17 mS/cm [2], Li2S-P2S5: 17 mS/cm [3]). These solid electrolytes have served as a conducting electrolyte layer for all-solid-state batteries [4].
The practical use of solid electrolytes in batteries has been limited due to their complicated and expensive synthesis procedures. Conventional solid electrolyte requires not only several sintering processes at elevated temperatures but also many compression steps under high pressures for making a solid electrolyte layer. Furthermore, to make a full cell including anode and cathode materials, additional compression steps are indispensable. The complex synthesis processes requiring high energy and cost is the major huddle for implementation. Furthermore, laboratory fabricated solid state batteries suffer from low specific energy due to the large excess of electrolyte in both the separator and composite electrodes.
In this work, we have developed an efficient method to form a thin solid electrolyte layer directly on Li metal using the liquid coating techniques. The formation of LPS (Li2S-P2S5) based electrolyte is achieved by rational design of the solvent and the Li, P, and S precursor ratios. The solution electrolyte can be directly coated and formed on Li metal through the in-situ formation of the solid electrolyte layer, which does not require the complex synthesis process and high temperature sintering step. Layers of thickness of < 50 mm can be fabricated and electrochemical cycling of lithium is achieved. This liquid-phase coating is a simple and straightforward technique for making a thin solid electrolyte and can be applicable to anode surface with complex contours. The new liquid coating technique holds the promise to overcome the limitations of current state solid electrolytes.
[1] Kamaya, N. et al. A lithium superionic conductor. Nature Mater. 10, 682-686 (2011).
[2] Yamane, H. et al. Crystal structure of a superionic conductor, Li7P3S11. Solid State Ion. 178, 1163-1167 (2007).
[3] Seino, Y., et al. A sulphide lithium super ion conductor is superior to liquid ion conductors for use in rechargeable batteries. Energy Environ. Sci. 7, 627-631 (2014).
[4] M.Tatsumisago, et al. Recent development of sulfide solid electrolytes and interfacial modification for all-solid-state rechargeable lithium batteries. J. Asian Ceram. Soc. 1, 17-25 (2013).
9:45 AM - ES06.04.04
Development of a Novel Selective Synthesis of Solid Ionically Conductive Materials through Electrochemical Corrosion
Jacob Schneider 1 , Jeffrey Ma 1 , Amy Prieto 1 , James Neilson 1
1 , Colorado State University, Fort Collins, Colorado, United States
Show AbstractIn order to develop the next generation of solid-state energy storage devices, major improvements need to be made in fast ion conducting solid materials. There are a few general classes of solid state inorganic fast ion conductors which are currently under development, but all have shortcomings when it comes to properties, processability, and practicality for device inclusion. Improvement of these materials has been incremental, and the best materials generally rely on defects or lack of long range order, all of which make theoretical calculations to help guide discovery non-trivial. We are aiming to accelerate the discovery of new materials by developing a synthetic paradigm wherein the synthetic method selectively synthesizes materials with fast ionic conduction.
We employ electrochemical corrosion as a synthetic method to produce thin films of an ionic conductor directly onto an active electrode. To explain the concept I will first present successful proof of concept experiments using AgI as a test case. The corrosion of Ag electrodes (resulting in the formation of Ag ions, the desired mobile ion) in the presence of I-containing supporting electrolytes results in a wide array of interesting morphologies as current density, potential, and solution conditions are varied. These products have been characterized using electron microscopy, X-ray diffraction, and electrochemical impedance spectroscopy. If the reaction forms unfavorable products that are electrically and ionically insulating, the reaction will cease.
Secondary systems that will be presented include Cu2-xSe and Na3PS4. Both of these are known systems, but require more complicated electrochemical control (Cu2-xSe requires controlling oxidation from Cu0 to a mixed Cu+ and Cu2+ system), complicated air and water free solutions, and difficult precursors (Na3PS4). The short term outlook of this work is to develop the techniques and systems that can be used to synthesize known compounds. This method allows for faster screening of various systems, and should result in materials with multiple desired properties. The benefits to this approach are that this is a practical and scalable synthetic method in which there is the potential to have a full half-cell with a solid electrode and electrolyte as the product. In addition to fast-ionic conduction, the activation energy for the transport of the electrode material across the interface into the electrolyte must be sufficiently low, which is often an issue for inorganic solid electrolytes. Lastly, as the synthetic method targets desired properties rather than specific stoichiometries or structures, we are more likely to find amorphous materials, highly defected materials, and non-thermodynamic phases than current methods. This allows us to find systems that would not be predicted by current theoretical methods.
10:30 AM - ES06.04.05
Fabrication of Sub-Micrometer-Thick Solid Electrolyte Membranes of β-Li3PS4 via Tiled Assembly of Shape-Controlled Building Blocks
Zachary Hood 1 2
1 , Georgia Institute of Technology, Atlanta, Georgia, United States, 2 , Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States
Show AbstractSolid electrolytes are expected to improve future energy storage technologies in terms of safety, energy capacity, and power density Since solids generally have lower ionic conductivity than liquids, it is necessary to process them as ultrathin membranes in future battery configurations. Among the promising sulfide-based superionic conductors, β-Li3PS4 has been identified as a prime candidate for solid electrolyte membranes for its enhanced ionic conductivity on the order of 10-4 S/cm [1-3]. Here, we report a new strategy for fabricating sub-micrometer-thick membranes of β-Li3PS4 based on plate-like, nanoscale building blocks via tiled assembly, followed by warm pressing [4]. The β-Li3PS4 membranes not only show a desirable ionic conductivity but also compatibility with metallic lithium anode. Our results also highlight a new thin film technology that can be extended to other systems of materials.
References:
1. Liu, Z.; Fu, W.; Payzant, E. A.; Yu, X.; Wu, Z.; Dudney, N. J.; Kiggans, J.; Hong, K.; Rondinone, A. J.; Liang, C. Journal of the American Chemical Society 2013, 135, 975.
2. Hood, Z. D.; Wang, H.; Li, Y.; Pandian, A. S.; Paranthaman, M. P.; Liang, C. Solid State Ionics 2015, 283, 75.
3. Lin, Z.; Liang, C. Journal of Materials Chemistry A 2015, 3, 936.
4. Hood, Z.D.; Wang, H.; Samuthira Pandian, A.; Peng, R.; Wu, Z.; Dudney, N.J.; Chi, M., Liang, C.; Xia, Y. In preparation, 2017.
10:45 AM - *ES06.04.06
High Ionic Conductivity Solid Polymer Electrolyte for All-Solid-State Li-Ion Battery
Yu Zhu 1
1 Department of Polymer Science, University of Akron, Akron, Ohio, United States
Show AbstractLithium-ion batteries (LIBs) have become one of the technological advancements that are inseparable from our daily lives, valuable features such as long cycle stability, high power and energy density are being pursued in order to further extend the usage time for portable electronics and electric vehicles. With the recent incidences in battery failure due to presumably lithium dendrite formation that eventually lead to thermal runaway, solid-state electrolyte (SSE) is one of the promising candidates to at once provide high lithium ionic conductivity and achieve a safer battery due to its all-solid-state nature. Herein, we report the combination of the bis(trifluoromethane)sulfonamide lithium salt (LiTFSI), glutaronitrile (GN) plastic crystal and crosslinkable copolymer host as the SPE with the addition of LiBOB salt as the additive. The SPE exhibited an ionic conductivity of ~ 1.0×10-3 S/cm at room temperature. Lithium plating and stripping experimentation also exhibited an impressive electrochemical stability over 1300 hours. The SPE membrane with the lithium metal and LFP cathode showed excellent performance of ~137 mAh/g at 0.25 C in the first 100 cycles at 30 oC while giving a 90% capacity retention at its 300th cycle.
11:15 AM - ES06.04.07
The Role of Carbon in Modifying Ionic Conductivity in Polyborane Solid Electrolytes
Joel Varley 1 , Kyoung E. Kweon 1 , Patrick Shea 1 , Prateek Mehta 2 , Mirjana Dimitrievska 5 3 , Vitalie Stavila 4 , Terrence Udovic 5 , Brandon Wood 1
1 , Lawrence Livermore National Laboratory, Livermore, California, United States, 2 Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana, United States, 5 NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland, United States, 3 , National Renewable Energy Laboratory, Golden, Colorado, United States, 4 , Sandia National Laboratories, Livermore, California, United States
Show AbstractPolyborane salts based on B12H122– and B10H102– anions demonstrate extraordinary Li and Na superionic conductivity that make them attractive as electrolytes in all-solid-state batteries. Their rich chemical and structural diversity creates a versatile design space that could be used to optimize materials with even higher conductivity at lower temperatures; however, many mechanistic details remain enigmatic, including reasons why certain modifications like the incorporation of carbon (as carboborane CB11H12– and CB9H10– anions) lead to lower superionic phase transition temperatures and improved ionic conductivities. Here, we use a combination of ab initio molecular dynamics simulations (AIMD) and quasielastic neutron scattering (QENS) to broadly explore the influence of carbon on both cation and anion dynamics and the resulting ionic conductivity. Our results identify the dual roles of carbon in enhancing short-range repulsive cation-anion and anion-anion interactions that drive local order in the carboboranes while facilitating rapid anion reorientations that lower the superionic transition temperature relative to their polyborane analogs. Our results support that the interplay between anion reorientational dynamics with cation-anion and anion-anion interactions on multiple length scales are responsible for the high conductivity observed in these systems.
This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
11:30 AM - ES06.04.08
Interface Chemistry of Solid Electrolyte/Electrode Interfaces Probed by X-Ray Spectroscopy and Scattering
Gulin Vardar 1 , Jiayue Wang 1 , Qiyang Lu 1 , Rachel Seibert 2 , Zhengrong Lee 2 , Jeff Terry 2 , Yet-Ming Chiang 1 , Bilge Yildiz 1
1 , Massachusetts Institute of Technology, Cambridge, Massachusetts, United States, 2 , Illinois Institute of Technology, Chicago, Illinois, United States
Show AbstractSolid-state lithium-ion batteries hold great promise for obtaining higher energy densities but the power density is currently limited by the electrode-electrolyte interfaces. [1] The high resistances at solid-state lithium-ion battery interfaces are hypothesized to be due to chemical mixing, space charge formation, or secondary phase formation. [2,3] Although several secondary phases have been proposed theoretically, there is the need for a systematic experimental work studying the secondary phase formation as a function of temperature and applied voltage. Extended x-ray absorption fine structure spectroscopy (EXAFS) is a unique capability that allows us to probe the fine structure around the atoms at the electrode-electrolyte interface and their oxidation states. Depth-sensitive x-ray absorption spectroscopy allows us to probe the changes in structure at the interface even if the secondary phases are not crystalline. This work studies the interface between Li7La3Zr2O12 (LLZO) and LiCoO2 (LCO) sputtered thin films. Current results indicate a temperature induced formation of secondary phases at this interface, initiating as low as at 300 oC, and causing substantial increases in the interface resistance. Correlations of these interface chemistries to electrochemical charge transfer is being established.
References
[1] Cheng, L. et al. Phys. Chem. Chem. Phys. 16, (2014)18294–18300.
[2] Miara, L. J., et al. Chem. Mater. 27, (2015) 4040–4047.
11:45 AM - ES06.04.09
Ultrathin Polymer Solid Electrolyte for Lithium-Ion Batteries
Yifan Gao 1 , Wyatt Tenhaeff 1
1 Chemical Engineering, University of Rochester, Rochester, New York, United States
Show AbstractLithium ion batteries are widely used for portable electronics, particularly laptops and mobile phones, due to their superior energy and power densities. As modern microelectronic devices and microelectronic mechanical systems (MEMS) advance further, the bottleneck to further miniaturization is often energy storage.1 While solid state thin film batteries offer remarkable electrochemical performance and long term stability, they are limited by areal capacity (mAh/cm2).2 Solid state three dimensional lithium ion micro-batteries (3D micro-batteries, for short) are an attempt to realize the exceptional electrochemical performance of thin film batteries by fabricating solid state lithium ion cells on high specific surface area. The rationale is to exploit all three dimensions of space, while maintaining short ionic diffusion lengths using conformal, laminated layers as in thin film batteries. The challenge to realizing these battery designs is the preparation of conformal, ultrathin solid-state electrolytes that physically separate the two electrodes while allowing rapid ion transport. Using initiated chemical vapor deposition, 800nm-thick crosslinked polymer thin films composed of poly (methacrylic acid-co-ethylene glycol diacrylate) were synthesized. These films were transformed to lithium-bearing polyelectrolytes through H+/Li+ ion exchange in a 1M LiOCH3 solution in methanol. Fourier transform infrared spectroscopy (FTIR) characterization was used to determine the chemical composition of the copolymer film and confirm successful ion exchange through analysis of the carbonyl vibrational bands associated with the C=O stretch in the acid and salt forms of the polymer. The ionic conductivity of the Li+-exchanged polymer was determined to be 9.5x10-9 S/cm at 60°C and its activation energy was 0.725eV. The electrochemical stability of this electrolyte was determined through cycling in thin film batteries. The effect of crosslinking densities in these films (the mole fraction of ethylene glycol diacrylate) on electrochemical properties is currently underway. Current efforts to further enhance ionic conductivity will also be discussed.
1. Letiche, M.; Eustache, E.; Freixas, J.; Demortiere, A.; De Andrade, V.; Morgenroth, L.; Tilmant, P.; Vaurette, F.; Troadec, D.; Roussel, P.; Brousse, T.; Lethien, C., Atomic Layer Deposition of Functional Layers for on Chip 3D Li-Ion All Solid State Microbattery. Adv. Energy Mater. 2017, 7 (2), 12.
2. Ferrari, S.; Loveridge, M.; Beattie, S. D.; Jahn, M.; Dashwood, R. J.; Bhagat, R., Latest advances in the manufacturing of 3D rechargeable lithium microbatteries. Journal of Power Sources 2015, 286, 25-46.
ES06.05: Solid Electrolyte and Characterization
Session Chairs
Tuesday PM, November 28, 2017
Hynes, Level 2, Room 203
1:30 PM - ES06.05.01
A Flexible Solid Composite Electrolyte with Vertically Aligned and Connected Ceramic Channels for Lithium Batteries
Haowei Zhai 1 , Yuan Yang 1
1 , Columbia University, New York, New York, United States
Show AbstractUsing solid state electrolytes instead of organic liquid ones is a promising approach to realize safe rechargeable batteries with high energy density. Composite solid electrolytes, which are composed of polymer and ceramic electrolytes, are attractive, since they combine the flexibility of polymer electrolytes and high ionic conductivities of ceramic electrolytes. However, the overall conductivity is limited by the low conductive polymer matrix, especially when nanoparticles (NPs) are used. Thus, the geometry of ceramic component plays an important role to further enhance the conductivity of composite electrolytes. We report the vertically aligned and connected Li1+xAlxTi2−x(PO4)3 (LATP) NPs in the polyethylene oxide (PEO) matrix to maximize the ionic conduction, while maintaining the flexibility of the composite electrolyte. The aligned structure provides direct channels for lithium ions transport and improves the ionic conductivity significantly, which is fabricated by an ice-templating-based method. The overall conductivity reaches 0.52 × 10-4 S/cm, which is 3.6 times that of the composite electrolyte with randomly dispersed LATP NPs1. The composite electrolyte also shows enhanced thermal and electrochemical stability compared to the pure PEO electrolyte as well as good mechanical properties. This method opens a new approach to optimize ion conduction in composite solid electrolytes for next-generation rechargeable batteries.
Reference:
1. Zhai, H.; Xu, P.; Ning, M.; Cheng, Q.; Mandal, J.; Yang, Y. Nano Letters 2017, 17, (5), 3182-3187.
1:45 PM - ES06.05.02
Investigating the Mechanism for High Ionic Conductivity in Polyborane Solid Electrolytes
Patrick Shea 1 , Brandon Wood 1 , Joel Varley 1 , Kyoung E. Kweon 1
1 , Lawrence Livermore National Laboratory, Livermore, California, United States
Show AbstractA recently discovered class of materials based on polyborane anions and lithium or sodium cations have been found to show exceptional ionic conductivity, and are promising candidates for electrolytes in all solid state batteries. These materials become superionic after an order-disorder phase transition in which the anions become orientationally disordered. We use ab initio molecular dynamics simulations to investigate the nature of the order-disorder transition as well as the mechanism for cation transport. We find that orientational disorder of anions and configurational disorder of cations are strongly linked, with both becoming disordered and highly mobile above the transition temperature; the energy barriers for anion rotation and cation diffusion are found to be significantly lowered in the disordered phase. By scanning over a range of crystal structures, anion/cation combinations, and local defects, we find that introduction of defects though doping with different anions or cation vacancies suppresses formation of the ordered phase and has a favorable effect on both the phase transition temperature and cation mobility.
2:00 PM - ES06.05.03
Mechanical Properties and Ionic Mobility for Glass and Silica-Polymer Hybrid Electrolytes
Weimin Wang 1 , John Kieffer 1
1 , University of Michigan, Ann Arbor, Michigan, United States
Show AbstractSolid-state electrolytes (SSE) are critical for the development of the next-generation batteries. It is expected that SSE combine high ionic conductivity and mechanical stiffness. These two attributes, however, are reversely coupled for most materials, such as for example inorganic glasses. A detailed study of mixed network-former (MNF) oxide glass systems revealed that elastic deformations of the structure surrounding the migrating cation during the activated jump process are almost purely hydrostatic, and that in mechanically stiffer structures, fewer atoms tend to be affected by cation jump, which requires higher-frequency phonons to focus the thermal energy onto these participating atoms. Consequently, the activation energy is high and cation mobility low in stiff networks, and vice versa. To decouple the ionic conductivity from mechanical stiffness we synthesized hybrid materials, in which PEG polymer chains that are covalently grafted onto an amorphous silica backbone establish a spatial buffer between the phase responsible for mechanical stiffness and the charge carrier cation donors. To achieve the highest conductivities, in excess of 10-5 S/cm, the inorganic backbone must be continuous in three dimensions, which provides both for mechanical integrity and can accommodate large volume fractions of PEG. Here we provide a cumulative account of a systematic materials design effort, in which we sequentially implemented several important design aspects so as to identify their respective importance and influence on the materials performance characteristics.
2:15 PM - ES06.05.04
(PEO)16.LiCF3SO3+Ohara LICGC® Composite Polymer Ceramic Electrolyte for Lithium Secondary Batteries
Amaresh Samuthira Pandian 1 , Frank M. Delnick 1 , Nancy Dudney 1
1 Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States
Show AbstractSolid electrolytes are a promising alternative to flammable liquid electrolytes for high-energy lithium battery applications. Composite polymer ceramic electrolytes are essentially a blend of dispersed ceramic particles and polymer electrolytes that are expected to maintain the properties of the individual components like ionic conductivity and complement each other on properties like mechanical stiffness and chemical stability without compromising the cation transport. The introduction of ceramic fillers in polymer electrolyte enhanced the ionic conductivity and improved the interfacial stability of the polymer against metallic lithium due to the increased amorphous nature of the polymer host. [1] The filler materials range from non-conducting fillers like Al2O3, TiO2, SiO2 and ZrO2 [2, 3] to ion-conducting fillers like Li7La3Zr2O12, Li1.3Al0.3Ti1.7(PO4)3. [4, 5] Overall ionic conductivity of the electrolyte decreased with increase in filler quantity above a threshold limit, so the volume of filler is restricted to 20 vol%.
In contrast, we are interested in composite with a much higher loading of a ceramic electrolyte and just enough polymer to conduct cation from one conducting ceramic particle to another. The aim of this study is to use model materials that are highly pure, commercially available and establish the physical and electrochemical properties. A wet protocol using water as the carrier solvent was developed for obtaining composite ceramic polymer electrolyte using simple spray coating technique. This highly versatile and scalable method was used to fabricate composite electrolyte having a high volume fraction of the ion conducting Ohara Lithium Conducting Glass Ceramic (LICGC®) electrolyte in composite with polymer electrolyte based on polyethylene oxide and lithium trifluoromethane sulfonate. Tetraethylene glycol dimethyl ether is used in this study as a plasticizer with expectation of good stability with Lithium and enhanced ionic transport. We observed several folds increase in ionic conductivity of the polymer electrolyte when TEGDME is used as a plasticizer. Results obtained from physical, thermal and electrochemical investigations will be presented in detail.
References:
[1] Croce, F.; Appetecchi, G. B.; Persi, L.; Scrosati, B., Nature 1998, 394, 456.
[2] Bac, A.; Ciosek, M.; Bukat, M.; Marczewski, M.; Marczewska, H.; Wieczorek, W., J. Power Sources 2006, 159, 405.
[3] Syzdek, J.; Armand, M.; Marcinek, M.; Zalewska, A.; Zukowska, G.; Wieczorek, W., Electrochim. Acta 2010, 55, 1314.
[4] Nairn, K. M.; Best, A. S.; Newman, P. J.; MacFarlane, D. R.; Forsyth, M., Solid State Ionics 1999, 121, 115.
[5] Choi, J. H.; Lee, C. H.; Yu, J. H.; Doh, C. H.; Lee, S. M., J. Power Sources 2015, 274, 458.
Acknowledgements:
This work was supported by the U. S. Department of Energy (DOE-EERE), Vehicle Technologies Office (Advanced Battery Materials Research, Tien Duong). We thank Brion Hoffman, Ohara Corporation, for supplying ceramic electrolyte powders.
2:30 PM - ES06.05.05
Fast Na-Ion Conducting NASICON-Based Electrolytes—Insights from Impedance Spectroscopy and 23Na NMR Relaxometry
Daniel Rettenwander 1 , Sarah Lunghammer 1 , Denise Prutsch 1 , Marie Guin 2 , Gunther Redhammer 4 , Frank Tietz 2 , Jurgen Fleig 3 , Martin Wilkening 1
1 Institute for Chemistry and Technology of Materials (ICTM), Graz University of Technology, Graz, Styria, Austria, 2 Institute of Energy and Climate Research, Forschungszentrum Jülich GmbH, Jülich Germany, 4 Department of Chemistry and Physics of Materials, University of Salzburg, Salzburg Austria, 3 Institute for Chemical Technologies and Analytics, Vienna University of Technology, Vienna Austria
Show AbstractMuch scientific attention is devoted to the development of all-solid state batteries (ASSB) as important and superior alternative to electrochemical cells relying on aprotic liquid electrolytes. Current research focuses on Li+-based battery systems because of their high energy density. The growing demand for such systems, especially if we take into account the new interest in stationary applications, might, however, increase the price of such systems drastically. Therefore, and because of environmental sustainability, much effort has recently been put into the development of alternatives using, for example, sodium as ionic charge carrier. The high abundance of Na is expected to lead to low costs. Among the inorganic Na+ electrolytes, NASICON-structured ones1 represent the most promising candidates to realize Na+-based ASSB. It is, however, imperative to understand the underlying ion transport processes to improve ionic mobility by crystal chemical engineering. Here we studied single crystalline Na3Sc2(PO4)3 (NSP) as well as several polycrystalline samples of Na3Sc2(SiO4)(PO4)2 (NSSP) and Na3Zr2(SiO4)2(PO4) (NZSP)2-4 by means of (microcontact) impedance and/or 23Na NMR spectroscopy to study the bulk and grain boundary processes at both the macroscopic and atomic scale. For example, we found that (i) changes in the thermal activation of the Na+ conductivity of NSP caused by phase transitions as observed in literature (e.g., Ref 3] cannot be related to bulk processes, (ii) via 23Na spin-lock NMR fast diffusion processes can be probed that corroborate ionic conductivities in the order of several mS/cm at ambient temperature. The latter is supported by Na+ transference numbers close to 1, as has been proved by potentiostatic polarization experiments.
[1] H.Y.P. Hong, Mat. Res. Bull. 11 (1976) 173-182
[2] M. Guin, F. Tietz, J.Power Sources 273 (2015) 1056-1064.
[3] J.M. Winaud, A. Rulmont, P. Tarte, J.Mater. Sci. 25 (1990) 4008-4013
[4] M.A. Subramanian, P.R. Rudolf, A. Clearfield, J.Solid State Chem. 60 (1985) 172-181.
3:15 PM - *ES06.05.06
Microscopic Insights into Conductivity and Stability of Solid Electrolyte Interfaces
Miaofang Chi 1 , Nancy Dudney 1 , Jeff Sakamoto 2
1 , Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States, 2 , University of Michigan–Ann Arbor, Ann Arbor, Michigan, United States
Show AbstractDespite their different chemistries, novel energy-storage systems, e.g., Li- air, Li-S, all-solid-state Li batteries, etc., share the same concept of using solid electrolyte materials to enable the use of lithium metal. An ideal solid electrolyte material must be highly ionically conductive and exhibit desirable stability with metallic lithium. Over the past several decades, new solid electrolyte materials were developed that demonstrated high conductivity, which is comparable to that of organic liquid electrolytes. However, unexpectedly high resistivity from grain boundaries and electrolyte-lithium interfaces is often observed and is the major limitation in realizing the practical application of these materials. Due to spatial confinement and structural and chemical complications, experimentally probing these interfaces is challenging. Thus, the exact origins of the interfacial resistivity is unclear. Here, in situ and atomic-resolution scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) are used to study these interfaces. Oxide solid electrolytes, including Li0.33La0.55TiO3 (LLTO) and Al-Li7La3Zr2O12 (LLZO), and LIPON, are used as prototype materials. The atomic-scale origin of the high grain boundary resistivity in polycrystalline LLTO was revealed to be due to the formation of a TiOx binary oxide layer with a thickness of 2-3 unit cells. This layer is deficient in Li ions and does not contain adequate vacancy sites for Li+ transport, significantly lowering the overall ionic conductivity in LLTO. At the LLZO-Li interface, an ultra-thin, self-limiting interfacial layer was discovered by utilizing in situ STEM, serving as a passivation layer that stabilizes the interface. In addition to chemical and structural transformations, interfacial polarization could also significantly influence mass transport and charge transfer behavior at ionic interfaces. A direct experimental approach to measure this space-charge effect, however, is not yet been feasible. In this talk, a new electron microscopy technique, which promises atomic-scale investigations of the space-charge layer at ionic interfaces will be introduced.
Acknowledgement
Research sponsored by the Materials Sciences and Engineering Division, Office of Basic Energy Sciences, U.S. Department of Energy. Microscopy performed as part of a user project at Oak Ridge National Laboratory’s Center for Nanophase Materials Sciences (CNMS), which is a U.S. DOE User Facility.
3:45 PM - ES06.05.07
Nuclear Magnetic Resonance Investigations of a Next-Generation Lithium Polymer Electrolyte
Stephen Munoz 1 2 , Mallory Gobet 1 , Steven Greenbaum 1 , Mike Zimmerman 3 , Randy Leising 3 , Zachary Hood 1
1 , Hunter College of CUNY, New York, New York, United States, 2 , The Graduate Center of CUNY, New York, New York, United States, 3 , Ionic Materials, LLC, Woburn, Massachusetts, United States
Show AbstractThe Li-ion battery has served as the workhorse of many industries for a generation. The technology has advanced incrementally over the years, but the underlying chemistry has undergone only minimal changes since its commercialization in the early 90’s. A novel solvent-free polymer electrolyte developed by Ionic Materials, LLC threatens to shift this paradigm. The polymer electrolyte is based on a crystalline thermoplastic polymer which is treated with an oxidizing agent and then reacted with a lithium salt. This electrolyte displays transport properties suitable for commercial battery use, while retaining the mechanical and safety advantages associated with a solid, and sufficient electrochemical stability to allow its use with Li-metal and high voltage intercalation electrodes. We report here Nuclear Magnetic Resonance (NMR) investigations of this polymer electrolyte. Pulsed-field gradient self-diffusion studies, in tandem with relaxometry and magic angle spinning (MAS), allow characterization of the structure and dynamics of this revolutionary material. Our measurements show room-temperature Li+ self-diffusion coefficients on the order of 10-9 m2/s (an order of magnitude higher than previously reported solid electrolyte candidates), as well as cation transference numbers exceeding 0.5. We have also established that the ionic motion is decoupled from polymer segmental or chain motion, in contrast to the mechanism governing ionic transport in the widely studied polyether-based electrolytes. We discuss some of the challenges of studying this material, as well as the implications of the results for its suitability as an electrolyte for secondary Li metal batteries.
4:00 PM - ES06.05.08
Investigation of the Degradation Mechanism for Solid-State Li-Ion Batteries by Chemical Composition Mapping
Chen Gong 1 , Elliot Fuller 2 , Farid El Gabaly 2 , Zinab Jadidi 1 , Alec Talin 2 , Marina Leite 1
1 , University of Maryland, College Park, Maryland, United States, 2 , Sandia National Laboratories, Livermore, California, United States
Show AbstractSolid-state Li-ion batteries (SSLIBs) have the potential to meet our energy storage demand due to the high power density (>250 W/kg) and enhanced safety. However, the degradation mechanism for SSLIBs upon cycling is still under study. To understand the irreversible lithiation process upon cycling, we combine scanning/transmission electron microscopy (S/TEM), X-ray photoelectron spectroscopy (XPS), conductive atomic force microscopy (c-AFM), and time-of-flight secondary ion mass spectroscopy (ToF-SIMS) to determine where the Li ions are within each battery component for SSLIBs with Al and Si anodes. We find an Al-Li-O capping layer formed on the AlLi alloy at the top surface of the Al anode using S/TEM and XPS [1, 2]. c-AFM indicates the insulating nature of the Al-Li-O alloy, thus, leading to the dramatic capacity fading during charging/discharging. Nevertheless, SSLIBs with Si anodes show an impressive electrochemical performance, with a capacity retention of >92% and a Coulombic efficiency of ~98% after 100 cycles [2]. Further, we directly map the Li ions by ToF-SIMS and identify where the irreversible lithiation occurs. We determine the Li distribution within all active layers at three state-of-charge: pristine, charged, and cycled. We observe that Li ions distribute non-uniformly upon the first charging within the anode and are trapped after cycling, explaining the capacity loss for the device [3]. Overall, our results provide significant information about where the irreversible reaction takes place and will contribute to the design of energy storage devices with larger capacity and longer lifespan.
[1] M. S. Leite et al., J. Mater. Chem. A 2014, 2, 20552. i-Cover
[2] C. Gong et al., ACS Appl. Mater. Interfaces 2015, 7, 26007. Cover
[3] C. Gong et al., In preparation 2017
4:15 PM - ES06.05.09
Why is Lipon Electrochemically Stable when Cycled vs Li Metal?
Andrew Westover 1 , Andrew Kercher 1 , Michael Naguib 1 , Gabriel Veith 1 , Nancy Dudney 1
1 , Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States
Show AbstractIn 2015, J. Li and N. Dudney et al.1 demonstrated that lithium phosphorus oxynitride (Lipon) in conjunction with a LiMn1.5Ni0.5O4 cathode can be cycled against a Li anode for over 10,000 cycles while maintaining over 90% of the initial capacity with a coulombic efficiency greater than 99.98%. While other solid state electrolytes (SSE) have recently been shown to have exceptional ionic conductivities, none have reproduced Lipon’s stability with Li metal.2 The two most common failure mechanisms are dendrite growth along the grain boundaries3 and chemical instability with Li metal.4 In order to elucidate why so many SSE electrolytes fail where Lipon succeeds, we report here our work in isolating and identifying the origin of Lipon’s resilience when in contact with Li metal. Using Lipon-like electrolytes based on Li, Si, P, B, O & N we investigate the effect of grain boundaries, the importance of nitrogen doping, and the difference between sputter deposited and traditional glass and ceramic processed electrolytes. This study lays important groundwork that could potentially enable the implementation of SSE that have exceptional ionic conductivity in full cell Li metal batteries.
1. J. Li, C. Ma, M. Chi, C. Liang and N. J. Dudney, Advanced Energy Materials, 2015, 5.
2. J. C. Bachman, S. Muy, A. Grimaud, H.-H. Chang, N. Pour, S. F. Lux, O. Paschos, F. Maglia, S. Lupart and P. Lamp, Chemical reviews, 2015, 116, 140-162.
3. F. Aguesse, W. Manalastas, L. Buannic, J. M. Lopez del Amo, G. Singh, A. Llordes and J. A. Kilner, ACS Applied Materials & Interfaces, 2017.
4. M. Nagao, A. Hayashi and M. Tatsumisago, Electrochemistry Communications, 2012, 22, 177-180.
Acknowledgement:
This work was supported by the IONICS program of ARPA-E. The authors thank Dr. Paul Albertus at ARPA-E for support and advice.
Symposium Organizers
Yan Wang, Worcester Polytechnic Institute
Chang-Jun Bae, Korea Institute of Materials Science
Juergen Janek, Justus-Liebig Univ-Giessen
Jun Wang, A123 Systems, LLC
ES06.06: Solid-State Batteries
Session Chairs
Chang-Jun Bae
Jeff Sakamoto
Wednesday AM, November 29, 2017
Hynes, Level 2, Room 203
8:30 AM - *ES06.06.01
Safe, High-Energy-Density, Solid-State Li Batteries
Eric Wachsman 1
1 , University of Maryland, College Park, Maryland, United States
Show AbstractWe have developed transformational, and intrinsically safe, solid-state Li batteries (SSLiBs), by incorporating high conductivity garnet-type solid Li-ion electrolytes into tailored tri-layer microstructures, by low-cost solid oxide fuel cell (SOFC) fabrication techniques to form electrode supported dense thin-film (~10μm) solid-state electrolytes. The microstrucurally tailored porous garnet scaffold support increases electrode/electrolyte interfacial area, overcoming the high impedance typical of planar geometry SSLiBs resulting in an area specific resistance (ASR) of only ~2 Ωcm-2 at room temperature. The unique garnet scaffold/electrolyte/scaffold structure further allows for charge/discharge of the Li-metal anode and cathode scaffolds by pore-filling, thus providing high depth of discharge ability without mechanical cycling fatigue seen with typical electrodes. Moreover, these scalable multilayer ceramic fabrication techniques, without need for dry rooms or vacuum equipment, provide for dramatically reduced manufacturing cost.
Fabrication of supported dense thin-film garnet electrolytes, their ability to cycle Li-metal at high current densities with no dendrite formation, and results for Li-metal anode/garnet-electrolyte based batteries with a number of different cathode chemistries will be presented.
9:00 AM - ES06.06.02
Amorphous LiCoO2-Based Positive Electrode Materials with Good Formability for All-Solid-State Rechargeable Batteries
Akitoshi Hayashi 1 , Kenji Nagao 1 , Yuka Nagata 1 , Atsushi Sakuda 1 , Masahiro Tatsumisago 1
1 , Osaka Prefecture University, Osaka Japan
Show AbstractAll-solid-state rechargeable lithium batteries attract much attention because of their high safety, long cycle life, versatile geometry and high energy density. To increase energy density of the batteries, the use of positive electrode active materials with high capacity and the increase of their content in a positive electrode layer are desired. Good formability of active materials is also important to form close solid-solid interfaces with solid electrolytes. Amorphous materials have a potential of an electrode active material because of their high capacity and good cyclability based on free volume in amorphous structure. In fact, amorphous transition metal sulfides such as TiS3 functioned as an active material with high capacity. They have good formability and electrical conductivity, and thus a positive electrode layer with only amorphous TiS3 without any carbon conductive additives and solid electrolytes was applied to a solid-state cell. The Li-In / Li3PS4 / amorphous TiS3 cell prepared by cold pressing without any high-temperature sintering processes exhibited a reversible capacity of 550 mAh/g for 10 cycles at 25oC [1]. Moreover, we have found novel amorphous transition metal oxide active materials with good formability and capacity [2]. Amorphous Li1.2Co0.8S0.2O2.4 (80LiCoO2-20Li2SO4 (mol%)) materials, where cubic-LiCoO2 nanoparticles (10 nm in size) were dispersed in an amorphous matrix, were prepared by ball-milling for the mixture of crystalline LiCoO2 and Li2SO4. A dense positive electrode layer with only Li1.2Co0.8S0.2O2.4 was formed by cold pressing. An all-solid-state oxide cell (Li-In / Li3BO3-based solid electrolyte / amorphous Li1.2Co0.8S0.2O2.4) operated as a secondary battery at 100oC, with an average discharge potential of 3.3 V (vs. Li+/Li) and the initial discharge capacity of about 160 mAh/g. This paper reports electrochemical properties and structure analyses of amorphous LiCoO2-based positive electrodes for all-solid-state lithium batteries.
References
[1] T. Matsuyama, M. Deguchi, K. Mitsuhara, T. Ohta, T. Mori, Y. Orikasa, Y. Uchimoto, Y. Kowada, A. Hayashi and M. Tatsumisago, J. Power Sources, 313 (2016) 104.
[2] K. Nagao, A. Hayashi, M. Deguchi, H. Tsukasaki, S. Mori, and M. Tatsumisago, J. Power Sources, 348 (2017) 1.
9:15 AM - ES06.06.03
Electrochemical Mechanism for All-Solid Lithium Sulfur Batteries
Erika Nagai 1 , Timothy Arthur 1 , Koji Suto 1 , John Muldoon 1 , Tomoya Matsunaga 1
1 , Toyota, Ann Arbor, Michigan, United States
Show AbstractAdvances in hybrid technology and a demand for a reduction in greenhouse gas emissions has driven diversification in energy storage research. To exceed the limits of current hybrid, plug-in hybrid and electric vehicles, new battery systems with high energy density and substantial cycle-life are required. Recently, lithium sulfur (Li-S) battery has attracted attention due to its high theoretical capacity (1673mAh/g) and the potential low cost.1,2 However, long cycle-life is hindered by the dissolution and shuttling of polysulfides, and continuous electrolyte decomposition on the Li metal surface. By utilizing a solid-state electrolyte, the major issues surrounding Li-S batteries are solved.
Solid-state electrolytes, including polymer electrolytes, gel electrolytes and single-ion conducting ceramics, have been intensely studied for energy storage.3 The potential benefits are wide-operating windows, active material dissolution prevention and metal dendrite inhibition. However, low ionic conductivity and interfacial stability are key challenges to overcome. Recently, ionic conductivities rivaling liquid based-systems have been observed for the sulfide-based, glass-ceramic LGPS4, encouraging continued research into solid-state batteries using sulfide-based solid-electrolytes.
Here, we will present electrochemical properties of solid-state Li-S batteries using glass-ceramic, sulfide-based solid-electrolyte and a modified lithium metal anode. The potential of the system is illustrated through the continuous galvanic cycling at 1C cycling rate (> 4.0 mA cm-1), good capacity retention and high-areal sulfur loading. A thorough analytical study on the electrochemical discharge reveals a mechanism which differs from typical liquid-based systems. Finally, we will present potential solutions to further improve all-solid Li-S batteries for vehicle electrification.
[1] Manthiram, A., et al. Chem. Rev., 114, 11751-11787 (2014)
[2] Pang, Q., et al. Nature Energy, 1, 16132 (2016)
[3] Manthiram, A., et al. Nature Reviews Materials, 2, 16103 (2017)
[4] Kamaya, N., et al. Nature Materials, 10, 682–686 (2011)
9:30 AM - ES06.06.04
Coupling between Electrochemistry and Mechanics in All-Solid-State Battery Materials
Frank McGrogan 1 , Tushar Swamy 1 , Sean Bishop 1 , Erica Eggleton 1 , Lukas Porz 1 , Xinwei Chen 1 , Yet-Ming Chiang 1 , Krystyn Van Vliet 1
1 , Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
Show AbstractLi-ion batteries that include all solid-state components show promise as an emerging energy storage technology, as the solid electrolyte can improve safety and enable longer cycle life than current batteries based on flammable and reactive liquid electrolytes. Mechanical compatibility and durability of the solid components during large intercalation-induced volume changes are key concerns. For example, deformation and fracture of the solid electrolyte during cycling is expected to slow Li-ion conduction and create pathways for dendritic growth of metallic Li that can short-circuit the device, while fracture of electrode particles or electrode-electrolyte interfaces can lead to loss of Li conduction into the particles. Identification and evaluation of key mechanical parameters of solid electrolytes and electrode materials is critical to predicting designs mitigating mechanical degradation.
Using instrumented nanoindentation, we characterized the mechanical behavior of two materials currently under consideration for all solid state batteries: the “high-voltage” Ni-substituted LiMn1.5Ni0.5O4 (LMNO) spinel electrode, which exhibits high energy density and charging rate capability, and 70/30 mol% Li2S-P2S5 (LPS) solid electrolyte, noted for high lithium conductivity at room temperature. Using a statistical grid indentation approach, we found that the addition of Ni and Fe to LiMn2O4 microparticles increases both Young’s modulus E and hardness H by ~40% [1]. For the LPS electrolyte, we measured E, H, and fracture toughness KIc as 18.5 +/- 0.9 GPa, 1.9 +/- 0.2 GPa, and 0.23 +/- 0.04 MPa m1/2, respectively, indicating that the LPS electrolyte is unique among other lithium solid electrolytes (polymers, oxides) in that it is both compliant and surprisingly brittle (low resistance to fracture) [2]. We will further discuss new results and understanding, including the relationship between these observed mechanical properties and integration of these materials as electrodes and solid electrolytes in all-solid-state batteries.
[1] McGrogan, F.P., Chiang, YM. & Van Vliet, K.J. J Electroceram (2016). doi:10.1007/s10832-016-0057-7
[2] McGrogan, F.P., Swamy, T., Bishop, S.R., Eggleton, E., Porz, L., Chen, X., Chiang, YM. & Van Vliet, K.J. Adv Energy Mat (2017). doi: 10.1002/aenm.201602011
9:45 AM - ES06.06.05
Transforming from Planar to Three-Dimensional Lithium with Flowable Interphase for Solid Lithium Metal Batteries
Yayuan Liu 1 , Yi Cui 1
1 , Stanford University, Stanford, California, United States
Show AbstractSolid-state lithium (Li) metal batteries are prominent for next-generation energy storage technology due to their much higher energy density with reduced safety risk. Previously, solid electrolytes have been intensively studied and several materials with high ionic conductivity have been identified. However, there are still at least three obstacles prior to making the Li metal foil-based solid-state systems viable, namely, high interfacial resistance at Li/electrolyte interface, low areal capacity and poor power output. Here, the problems are addressed by incorporating flowable interfacial layer and three-dimensional Li into the system. The flowable interfacial layer can accommodate the interfacial fluctuation and guarantee excellent adhesion at all time; while the three-dimensional Li significantly reduces the interfacial fluctuation from the whole electrode level (tens of micron) to local scale (submicron) and also decreases the effective current density for high-capacity and high-power operation. As a consequence, greatly improved electrochemical performance compared to the conventional Li foil counterpart can be achieved in both symmetric and full cell configuration, which is among the best reported values in the literature. Noticeably, solid-state full cells paired with high mass loading LiFePO4 exhibited at 80 oC a satisfactory specific capacity even at 5 C rate (110 mAh g-1) and 93.6% capacity retention after 300 cycles at a current density of 3 mA cm-2 using a composite solid electrolyte middle layer. And when a ceramic electrolyte middle layer was adopted, stable cycling with greatly improved capacity can even be realized at room temperature.
10:30 AM - *ES06.06.06
Fabrication of All-Solid-State Battery with Aero Sol Deposition Process for Cathode Layer
Kiyoshi Kanamura 1 , Kyoko Kozuka 1 , Mao Shoji 1 , Takeshi Kimura 1 , Hirokazu Munakata 1
1 Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, Hachioji, Tokyo, Japan
Show AbstractAll solid state battery with oxide cathode LMO2 (M=transition metal), Li metal anode and Li6.25Al0.25La3Zr2O12 (LLZ-Al) was fabricated by using LLZ-Al solid electrolyte pellet, Li metal foil and cathode layer fabricated by aero-sol deposition (AD) method. The LLZ-Al pellet used in this study had a thickness of 500 µm by using optimized conventional ceramic process. In the course of the LLZ-Al pellet, CO2 is absorbed by LLZ-Al powder due to high basicity of La element, resulting in a formation undesirable carbonates in the LLZ-Al powder. This carbonate formation strongly influenced on the properties of LLZ-Al pellet. In this study, the preparation of LLZ-Al pellet was carried out by a two-step sintering process. The LLZ-Al pellet had at least 95 % density and 10-4 S cm-1 ionic conductivity. The AD was carried out by using composite particles consisting of Li3BO3 (solid electrolyte) and LMO2 cathode materials. Li3BO3 (LBO) provided a low resistance of the cathode layer and also the low resistance of the interface between the cathode layer and LLZ-Al solid electrolyte pellet. LiCoO2 (LCO) and LiNixMnyCozO2 (x+y+z=1) were employed as cathode materials. In this study, a heat treatment after AD process was conducted to reduce resistances of the cathode layer. The melting temperature of LBO is 700 °C. Therefore, the heat treatment was performed at 750 °C for 1 hour. The Li anode was attached to the LLZ-Al pellet with a thin gold layer (thickness: 50 nm). After the aging of the cell at 100 °C for 1 hour, the all solid state cell was tested to evaluate their electrochemical behavior. An electrochemical impedance of the cell was reduced after the heat treatment. SEM observation exhibited a well-connected LMO2 and LBO. In addition, the gold layer for the Li metal anode was very useful to reduce the interfacial resistance between Li metal and LLZ-Al solid electrolyte. The discharge and charge test was carried out at 60 °C. The discharge and charge currents were 0.1 C rate (5~50 µA cm-2). Both cells can be able to discharge and charge at 60 °C. Especially, the cell with LCO showed an excellent performance. The cell after the heat treatment had a similar performance with the cell which used liquid electrolyte at 0.1 C rate. At the first cycle, an irreversible capacity was observed for LCO cathode in the cell with liquid electrolyte. In the case of the all solid state battery, the observed irreversible capacity was very small. The discharge and charge curves at the fourth cycle was not so different from those at the first cycle, indicating that the cycleability of this all solid state battery was good. However, the cathode layer thickness was only 10 ~ 20 µm. In order to realize a real high energy density of all solid state battery, the thick cathode layer should be prepared. We have employed aero sol generator for our AD equipment. By using new AD process, the thick cathode layer was prepared. The thickness of the cathode layer was 50 µm.
11:00 AM - ES06.06.07
Cold Sintering of Solid Ion Conductors for Lithium Metal Batteries
Wonho Lee 1 , Christopher Lyon 1 , Clive Randall 1 , Enrique Gomez 1
1 , The Pennsylvania State University, University Park, Pennsylvania, United States
Show AbstractAll-solid-state lithium batteries (ASSLBs) using solid ion conductors as electrolytes have attracted great interest to replace conventional Li-ion batteries (LIBs) that use organic liquid electrolytes because ASSLBs provide significant advantages, such as high energy density, non-flammability, and high electrochemical stability. A key issue for high-performance ASSLBs is developing solid state electrolytes with high ionic conductivity and bulk density. To this end, thermal sintering processes of ceramics at high temperatures (ca. 1000 oC) are typically required. High temperature sintering, however, limits ASSLB performance due to challenges in controlling stoichiometry due to Li volatility, lack of compatibility with soft materials and thereby precluding the synthesis of composites, and high processing costs. We have developed a simple and cost-effective sintering method (cold sintering process, CSP) that utilizes a small amount of solvent and uniaxial pressure to sinter LATP and LAGP at low temperatures (<150 oC). By controlling the cold sintering conditions, we can achieve densities > 95% of conventionally sintered samples and ionic conductivities of about 4 x 10-5 S/cm at room temperature. Characterization through electron microscopy suggests strong cohesion between grains, which is important to achieve high ionic conductivity. We have also assembled all-solid-state lithium batteries using our cold sintered solid electrolytes, and demonstrated successful cycling for high capacity batteries.
11:15 AM - ES06.06.08
Evaluation of the Electrochemical Behavior of Hot-Pressed 75Li2S-25P2S5 (LPS) Glassy Solid Electrolyte against Metallic Lithium
Regina Garcia-Mendez 1 , Jeff Sakamoto 1
1 , University of Michigan, Ann Arbor, Michigan, United States
Show AbstractThe (Li2S)-(P2S5) (LPS) family of compounds can exist in a wide range of compositions and degrees of crystallinity ranging from fully amorphous to fully crystalline. Of particular interest is the 75-25 LPS glass composition due to is high ionic conductivity (10-4 – 10-3 S cm-1) at room temperature, low interfacial resistance against metallic Li and ease of compaction. Based on these aspects, 75-25 LPS is one of the most promising ceramic electrolytes to enable all solid-state batteries. However, the maximum Li plating rate (or critical current density – CCD) has not been rigorously characterized to evaluate relevance for EVs. We hypothesize that the CCD is governed by microstructural defects in LPS, particularly the particle boundaries. Therefore, the purpose of this work is to correlate the effect of processing (densification) with the resulting microstructure and ultimately the CCD. In this work, 75Li2S-25P2S5 (mol %) amorphous powder was obtained through mechanochemical synthesis and hot pressed at 200°C at different densification pressures between 47 and 360 MPa. A dense (98% relative density) bulk glass was obtained and confirmed to lack crystallinity by X-Ray Diffraction and Differential Scanning Calorimetry. The mechanical properties of the bulk glass such as Young’s modulus, Shear Modulus and Hardness, were determined using Ultrasonic velocity measurements and nanoindentation. Also, the Li/LPS DC electrochemical stability was characterized as a function of current density between 0.05 and 1.0 mA cm-2. EIS analysis was conducted along with DC measurements to characterize the effects of Li metal penetration above the CCD. The goal of this work is to achieve a fundamental understanding of what governs the stability of the Li-LPS interface to enable the development of solid-state batteries using Li metal anodes.
11:30 AM - *ES06.06.09
Ion Conducting Ceramic Based Composite Electrolyte for High Voltage Pseudo-Solid-State Li (Na) Ion Batteries
Youngsik Kim 1 2 , Hyun Woo Kim 3 , Young Jun Lim 3
1 , UNIST, Ulsan Korea (the Republic of), 2 Energy Materials and Devices Lab, TOONE Corporation, Ulsan Korea (the Republic of), 3 Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan Korea (the Republic of)
Show AbstractConcerning the safety aspects, the present Li (Na) ion battery technologies, which use non-aqueous electrolytes causing leakage and flammable owing to thermal runaway, are obligatory to use in high power applications viz., electric vehicles (EVs), and grid energy storage applications. All solid-state batteries are an effective way to solve these problems due to the stability of the material itself. Especially, ceramic solid electrolytes have been investigated as an alternative electrolyte for Li (Na) ion batteries due to high voltage stability, thermal stability, and provide fast ion transportation. However, it is also suppressed by its critical issue of grain boundary resistance due to instable contact between solid-solid interfaces Currently, all solid-state batteries have been applied to only limited special systems to reduce the interfacial resistance such as high-pressure cell or thin film battery of atomic unit. Therefore, it is necessary to develop a new design of battery that can solve the interfacial resistance problem of the solid electrolyte and be easily applicable to the process.
In this work, we designed a new type of composite electrolyte combining a high amount of ion conducting ceramic particles (~80 wt%) with a small amount of ion conducting liquids (~20 wt%). It was observed that the ceramic component in the composite electrolyte acted as the main pathways for ion-tranport, and the liquid one reduced the interfacial resistance between the ceramic particles. This new type of composite electrolyte is in a quasi-solid state layer without any leakage of the liquid component. The optimized composite electrolyte revealed superior thermal stability (> 350 °C), ionic conductivity of 0.4 × 10–3 S cm–1 and impressive electrochemical stability with a voltage window of 5.5 V. The fabricated composite electrolyte cells (Li/LiCoO2) showed good capacity retention (130mAh g-1) up to 150 cycles. Expanding the scope of the present study, the unique property of the composite electrolyte was also demonstrated in a Swagelok-type bipolar high-voltage (> 8 V) pseudo-solid-state LIB. This composite electrolyte approach was also examined in a Na-ion cell (Na/Na1.0Li0.2Ni0.25Mn0.75O2), showing superior thermal stability as well as a high voltage (> 8 V) at bipolar stacked pseudo-solid-state NIB. These results show that this new type of composite electrolyte approach could not only ensure all advantages of all-solid-state batteries, but also circumvent the issues due to the use of liquid electrolytes.
ES06.07: Interface
Session Chairs
Wednesday PM, November 29, 2017
Hynes, Level 2, Room 203
1:30 PM - *ES06.07.01
Analyzing the Stability and Kinetics of the Li Metal-Solid Electrolyte Interface
Jeff Sakamoto 1 2 3
1 Mechanical Engineering, University of Michigan–Ann Arbor, Ann Arbor, Michigan, United States, 2 Materials Science and Engineering, University of Michigan–Ann Arbor, Ann Arbor, Michigan, United States, 3 Macromolecular Science and Engineering, University of Michigan–Ann Arbor, Ann Arbor, Michigan, United States
Show AbstractThe demand for high energy density, safe, and low cost batteries is ever-increasing. Li-ion is a promising technology to meet near term energy storage needs, however future applications will require a step-change increase in battery performance. While a small number of solid electrolytes exhibit fast ion conductivity (~1mS/cm at 298K), few are stable against Li metal. The garnet-type solid electrolyte, based on the nominal formula Li7La3Zr2O12 (LLZO), is unique in that it is a fast ion conductor and is also stable against Li. Moreover, LLZO exhibits a shear modulus (60 GPa) that is 20 times higher than metallic Li (5 GPa), which should be sufficient to suppress Li metal penetration according to the Monroe-Newman model. It is also believed that LLZO may also be stable at high potentials matching the redox potential of conventional Li-ion cathodes and perhaps high voltage cathodes.
Enabling Li metal in combination with conventional cathodes could produce batteries exceeding 500 Wh/kg and 1000 Wh/l. However, realizing the potential of solid-state battery technology requires a fundamental understanding of solid interface stability and kinetics and practical knowledge to develop strategies to fabricate large format cells employing dense ceramic electrolyte membranes. This presentation will discuss and summarize several recent findings that demonstrate the feasibility and highlight the challenges in developing a stable Li metal - solid electrolyte interface.
2:00 PM - ES06.07.02
Machine Learning-Driven Prediction of Electrodeposition Stability of Inorganic Solid Electrolytes with Li-Metal Anode
Zeeshan Ahmad 1 , Chinmay Maheshwari 1 , Venkatasubramanian Viswanathan 1
1 , Carnegie Mellon University, Pittsburgh, Pennsylvania, United States
Show AbstractInterest in solid electrolytes has tremendously increased due to the possibility of enabling the holy grail anode material for Li-based batteries – Li metal through a dendrite suppressing solid in contact. Recently, we showed that the stability of isotropic solid-solid interfaces against dendrite growth depends on a delicate interplay between shear modulus, molar volume ratio of metal and Poisson’s ratio of the solids[1]. An experimental or fully ab initio search for phases with stable electrodeposition is expensive and time-consuming. In this work, we use regression and machine learning models to predict the relevant properties of solid electrolytes using the structural features of the material. We trained our model using data on elastic tensors of ~300 materials calculated using density functional theory (DFT) retrieved from materials project database[2]. We generate a neural network model using structural features like crystal lattice, coordination numbers, bond ionicity and predict the full elastic tensor of the materials using these structural features. The structural features to be used for neural network were finalized using sequential feature reduction in a linear model and optimizing the cross-validation error. We find that volume per atom, packing fraction, Li bond ionicity, sub-lattice bond ionicity and formation energy per Li atom are some of the key factors determining the elastic tensor of Li-containing compounds. The neural network architecture used contained one input, one hidden and one output layer. Overfitting was avoided by using five-fold cross validation for determining hidden layer size. The overall predictive quality of the model was high as obtained by making predictions on the test set. Finally, using the model we make predictions of the elastic tensor and stability of ~12,000 inorganic solid-Li interfaces against dendrite growth. We conclude that machine learning approach greatly hastens the process of material discovery as compared to DFT calculations and experiments.
[1] Z. Ahmad and V. Viswanathan, Phys. Rev. Lett. 119, 056003 (2017).
[2] M. De Jong, W. Chen, T. Angsten, A. Jain, R. Notestine, A. Gamst, M. Sluiter, C. K. Ande, S. Van Der Zwaag, J. J. Plata, et al., Sci. Data 2, 150009 (2015).
2:15 PM - ES06.07.03
Lithium Dendrite Suppression in Solid Electrolytes
Fudong Han 1 , Jie Yue 1 , Xiangyang Zhu 1 , Chunsheng Wang 1
1 , University of Maryland, College Park, Maryland, United States
Show AbstractThe successful integration of lithium metal in a solid state battery is desired or even required for a competitive cell-level energy density. However, lithium dendrite tends to form at the grain boundaries or voids in both sulfide and oxide solid electrolytes. Many efforts have been done to improving the relative density, lowering the interfacial resistances, or modifying the lithium diffusion kinetics at the grain boundaries of the solid electrolytes. However, the critical current density, at which the cell will be short-circuited by dendrite formation, is still very low and is even much lower than that in the liquid-electrolyte based lithium cells. The origin for the dendrite formation remains elusive. Here we will show our understandings about the dendrite formation. With that, we then show two examples with our approaches: (1) improving the dendrite suppression capability of sulfide-based solid electrolyte by taking advantage of its electrochemical decomposition, (2) improving the dendrite suppression capability of Li7La3Zr2O12 solid electrolyte by grain boundary engineering.
3:30 PM - *ES06.07.04
The Stability of Solid Electrolyte with Li Metal, Especially for Oxide-Based SE
Byoungwoo Kang 1 , Habin Jung 1
1 , POSTECH, Pohang Korea (the Republic of)
Show AbstractThe demand for lithium secondary batteries having more safety and higher energy density has been increased for meeting the strong demand of novel applications such as electric vehicles and energy storage system. In this aspect, lithium ion batteries containing typical liquid electrolytes have fundamental limitations because liquid electrolytes can act as fuels in thermal runaway behavior leading to a fire or an explosion of battery and can be decomposed at high potential (> 4.5V) leading to the restricted use of high potential cathodes. Also, liquid electrolytes cause severe safety problems with Li metal, which is the best anode material for high energy density with low potential and high capacity because Li metal in liquid electrolytes easily leads to the formation of dendrite that can produce a short-circuit between cathode and anode. Applying proper oxide-based solid electrolytes can solve these problems and thereby many efforts have been gone to studies of solid electrolytes.
In this talk, I will discuss about the interfacial reactions of oxide-based solid electrolyte with lithium metal and the effect of the interfacial products on mechanical stability of SE and thermal stability of the cell with Li metal as an anode.
4:00 PM - ES06.07.05
Measuring the Adhesive Strength at the Interface of Li Metal Anodes and Li7La3Zr2O12 Solid Electrolytes
Michael Wang 1 , Jeff Sakamoto 1
1 , University of Michigan, Ann Arbor, Michigan, United States
Show AbstractLi metal anodes have long been recognized as an important requirement for future Li-ion battery chemistries as they offer drastic improvements in energy density over current Li-ion technology. Solid ceramic oxide electrolytes have shown the potential to mitigate the major problems that plague Li metal anodes in conventional electrolytes, namely dendrites and solid electrolyte interphase (SEI) side reactions. Currently there is a lack of understanding about the properties of the Li-electrolyte interface, which will be crucial to the development of materials or surface preparations for future solid state batteries. This work uses a unique mechanical testing setup to perform uniaxial tensile tests to measure the adhesive strength of Li metal on the surface of the Li7La3Zr2O12 (LLZO) solid electrolyte. We demonstrate a clear relationship between the adhesive strength with the area specific ionic resistance (ASR) at the Li-LLZO interface. It is shown that low interfacial resistances are strongly correlated to high adhesive strengths. At the lowest ASRs, the adhesive strengths are even comparable to the tensile strength of Li metal. Analysis of this relationship and of the fractured Li-LLZO interface provides insight into the interactions and wettability of Li metal on LLZO surfaces. This understanding will play an important role in the design of solid electrolyte surfaces for future solid state batteries.
4:15 PM - ES06.07.06
Interphase Formation and Chemo-Mechanical Processes in NCM-811 and Thiophosphate Solid-State Batteries
Raimund Koerver 1 2 , Wolfgang Zeier 1 2 , Juergen Janek 1 2
1 Institute of Physical Chemistry, Justus-Liebig Universität Giessen, Giessen, Hessen, Germany, 2 Center for Materials Research (LaMa), Justus-Liebig-Universität Giessen, Giessen, Hessen, Germany
Show AbstractAll solid-state lithium ion batteries may become long-term stable high-performance energy storage systems for the next generation of electric vehicles and consumer electronic, depending on the compatibility of electrode materials and suitable solid electrolytes.1 Nickel-rich layered oxides are nowadays the benchmark cathode materials for conventional lithium ion batteries because of their high storage capacity and the resulting high energy density, and their use in solid-state systems is the next necessary step.
We present the successful implementation of a Li[Ni,Co,Mn]O2 material with high nickel content (NCM-811) in a bulk-type solid-state battery with β-Li3PS4 as sulfide based solid electrolyte.2 We investigate the charge and discharge performance and demonstrate the important role of the resulting interfacial electrochemical characteristics. From in situ electrochemical impedance spectroscopy we conclude that a passivating cathode/electrolyte interphase layer forms upon charging and leads to an irreversible first cycle capacity loss, corresponding to a decomposition of the sulfide electrolyte. Evaluation of ex situ XPS data suggested that the majority of the passivating layer is developed during the first charge and grows slowly upon further cycling.
Furthermore, it was found that particles of the active material lose contact with the solid electrolyte due to the chemical contraction of NCM-811, which suggests that the particles are, therefore, no longer fully electrochemically addressed during subsequent cycles. Our results show that the observed capacity loss during the first cycle is a combination of changes in the chemical composition at the interface of the solid electrolyte (oxidation) as well as contraction of the NCM particles during delithiation (charging).
These findings do not only explain the first cycle capacity loss, they further underline the importance and so far underrated role of (electro-)chemo-mechanical effects in solid-state batteries.
(1) Zeier, W. G.; Janek, J. A Solid Future for Battery Development. Nat. Energy 2016, 1, 1–4.
(2) Koerver, R.; Aygün, I.; Leichtweiß, T.; Dietrich, C.; Zhang, W.; Binder, J.O.; Hartmann, P.; Zeier, W.G.; Janek, J. Capacity Fade in Solid-State Batteries: Interphase Formation and Chemomechanical Processes in Nickel-Rich Layered Oxide Cathodes and Lithium Thiophosphate Solid Electrolytes. Chem. Mater. 2017, 29, 5574-5582.
4:30 PM - ES06.07.07
Mechanism of Lithium Metal Penetration through Inorganic Solid Electrolytes
Tushar Swamy 1 , Lukas Porz 1 , Brian Sheldon 2 , Daniel Rettenwander 1 , Till Froemling 1 , Henry Thaman 1 , Stefan Berendts 1 , R. Uecker 1 , W Craig Carter 1 , Yet-Ming Chiang 1
1 , Massachusetts Institute of Technology, Cambridge, Massachusetts, United States, 2 , Brown University, Providence, Rhode Island, United States
Show AbstractVast energy density improvements may be achieved in Li-ion rechargeable batteries with lithium metal anodes. However, lithium metal batteries containing liquid electrolytes have been unsuccessful thus far due to safety concerns associated with short circuits that occur when Li dendrites grow through the liquid electrolyte during the charging process. In contrast, thin film batteries using Li metal negative electrodes with an inorganic solid electrolyte (e.g., LiPON) appear to withstand dendrite penetration over extended cycling [1]. Recently, however, multiple research groups have reported and investigated cases where ceramic solid electrolytes paired with a Li metal anode experience a short circuit event [2]. The mechanism by which short circuit events occur in all-solid-state Li-ion batteries is unclear.
Thus, in this project, the growth of lithium metal filled cracks through four types of solid electrolytes, glassy Li2S-P2S5 (LPS), β-Li3PS4, polycrystalline and single crystal Li6La3ZrTaO12 (LLZTO), was studied using galvanostatic electrodeposition experiments coupled with in-situ and ex-situ microscopy. An electrochemomechanical model for growth of lithium-filled cracks was developed. For current densities up to 5 mA/cm2, only the freshly cleaved surface of glassy LPS with no visible defects exhibits lithium metal deposition at the surface alone, without Li metal penetration into the solid electrolyte. All other surfaces of the LPS and LLZTO samples studied had observable defects, the maximum initial sizes of which were characterized. Electrodeposition of lithium at these surfaces is accompanied by the filling, and then propagation, of lithium metal filled cracks. The experiments and model suggest that above a critical current density, the Li plating overpotentials, and corresponding mechanical stresses, reach values sufficiently large to propagate pre-existing surface mechanical defects. Thus, the prevailing failure mechanism in brittle solid electrolytes is Griffith-like, and differs from the amplification of kinetic perturbations at the metal interface that results in dendrite growth in liquid electrolytes. Our results show that the shear-modulus criterion proposed by Monroe and Newman [3] for prevention of dendrites is not the determining factor for high modulus, brittle inorganic electrolytes studied here. We suggest that stabilization of inorganic solid electrolyte interfaces against lithium metal penetration will require scrupulous attention to minimize interfacial defects.
Acknowledgments
The authors gratefully acknowledge support from the US Department of Energy, Office of Basic Energy Science, through award number DE-SC0002633 (J. Vetrano, Program Manager).
References
1. J. Li, C. Ma, M. Chi, C. Liang, and N. J. Dudney, Adv. Energy Mater., 5, 1401408–1401414 (2015)
2. Y. Suzuki et al., Solid State Ionics, 278, 172–176 (2015)
3. C. Monroe and J. Newman, J. Electrochem. Soc., 151, A880–A886 (2004)